In the developed Roman law， the Convention， as soon as it was completed， was， in almost all cases， at once crowned with the Obligation， and so became a Contract； and this was the result to which contract-law was surely tending. But for the purpose of this inquiry， we must attend particularly to the intermediate stage —— that in which something more than a perfect agreement was required to attract the Obligation. This epoch is synchronous with the period at which the famous Roman classification of Contracts into four sorts —— the Verbal， the Literal， the Real， and the Consensual had come into use， and during which these four orders of Contracts constituted the only descriptions of engagement which the law would enforce. The meaning of the fourfold distribution is readily understood as soon as we apprehend the theory which severed the Obligation from the Convention. Each class of contracts was in fact named from certain formalities which were required over and above the mere agreement of the contracting parties. In the Verbal Contract， as soon as the Convention was effected， a form of words had to be gone through before the vinculum juris was attached to it. In the Literal Contract， an entry in a ledger or tablebook had the effect of clothing the Convention with the Obligation， and the same result followed， in the case of the Real Contract， from the delivery of the Res or Thing which was the subject of the preliminary engagement. The contracting parties came， in short， to an understanding in each case； but， if they went no further， they were not obliged to one another， and could not compel performance or ask redress for a breach of faith. But let them comply with certain prescribed formalities， and the Contract was immediately complete， taking its name from the particular form which it had suited them to adopt. The exceptions to this practice will be noticed presently.

　　I have enumerated the four Contracts in their historical order， which order， however， the Roman Institutional writers did not invariably follow. There can be no doubt that the Verbal Contract was the most ancient of the four， and that it is the eldest known descendant of the primitive Nexum. Several species of Verbal Contract were anciently in use， but the most important of all， and the only one treated of by our authorities， was effected by means of a stipulation， that is， a Question and Answer； a question addressed by the person who exacted the promise， and an answer given by the person who made it. This question and answer constituted the additional ingredient which， as I have just explained， was demanded by the primitive notion over and above the mere agreement of the persons interested. They formed the agency by which the Obligation was annexed. The old Nexum has now bequeathed to maturer jurisprudence first of all the conception of a chain uniting the contracting parties， and this has become the Obligation. It has further transmitted the notion of a ceremonial accompanying and consecrating the engagement， and this ceremonial has been transmuted into the Stipulation. The conversion of the solemn conveyance， which was the prominent feature of the original Nexum， into a mere question and answer， would be more of a mystery than it is if we had not the analogous history of Roman Testaments to enlighten us. Looking to that history， we can understand how the formal Conveyance was first separated from the part of the proceeding which had immediate reference to the business in hand， and how afterwards it was omitted altogether. As then the question and answer of the Stipulation were unquestionably the Nexum in a simplified shape， we are prepared to find that they long partook of the nature of a technical form. It would be a mistake to consider them as exclusively recommending themselves to the older Roman Lawyers through their usefulness in furnishing persons meditating an agreement with an opportunity for consideration and reflection. It is not to be disputed that they had a value of this kind， which was gradually recognised； but there is proof that their function in respect to Contracts was at first formal and ceremonial in the statement of our authorities， that not every question and answer was of old sufficient to constitute a Stipulation， but only a question and answer couched in technical phraseology specially appropriated to the particular occasion.

　　But although it is essential for the proper appreciation of the history of contract-law that the Stipulation should be understood to have been looked upon as a solemn form before it was recognised as a useful security， it would be wrong on the other hand to shut our eyes to its real usefulness. The Verbal Contract， though it had lost much of its ancient importance， survived to the latest period of Roman juris prudence； and we may take it for granted that no institution of Roman law had so extended a longevity unless it served some practical advantage. I observe in an English writer some expressions of surprise that the Romans even of the earliest times were content with so meagre a protection against haste and irreflection. But on examining the Stipulation closely， and remembering that we have to do with a state of society in which written evidence was not easily procurable， I think we must admit that this Question and Answer， had it been expressly devised to answer the purpose which it served， would have been justly designated a highly ingenious expedient. It was the promisee who， in the character of stipulator， put all the terms of the contract into the form of a question， and the answer was given by the promisor. “Do you promise that you will deliver me such and such a slave， at such and such a place， on such and such a day？” “I do promise.” Now， if we reflect for a moment， we shall see that this obligation to put the promise interrogatively inverts the natural position of the parties， and， by effectually breaking the tenor of the conversation， prevents the attention from gliding over a dangerous pledge. With us， a verbal promise is， generally speaking， to be gathered exclusively from the words of the promisor. In old Roman law， another step was absolutely required； it was necessary for the promisee， after the agreement had been made， to sum up all its terms in a solemn interrogation； and it was of this interrogation， of course， and of the assent to it， that proof had to be given at the trial —— not of the promise， which was not in itself binding. How great a difference this seemingly insignificant peculiarity may make in the phraseology of contract-law is speedily realised by the beginner in Roman jurisprudence， one of whose first stumbling-blocks is almost universally created by it. When we in English have occasion， in mentioning a contract， to connect it for convenience'' sake with one of the parties —— for example， if we wished to speak generally of a contractor —— it is always the promisor at whom our words are pointing. But the general language of Roman law takes a different turn； it always regards the contract， if we may so speak， from the point of view of the promisee. in Speaking of a party to a contract， it is always the Stipulator， the person who asks the question， who is primarily alluded to. But the serviceableness of the stipulation is most vividly illustrated by referring to the actual examples in the pages of the Latin comic dramatists. If the entire scenes are read down in which these passages occur （ex. gra. Plautus， Pseudolus， Act I. sc. i； Act IV. sc. 6； Trinummus， Act V. sc. 2）， it will be perceived how effectually the attention of the person meditating the promise must have been arrested by the question， and how ample was the opportunity for withdrawal from an improvident undertaking.

　　In the Literal or Written Contract， the formal act， by which an Obligation was superinduced on the Convention， was an entry of the sum due， where it could be specifically ascertained， on the debit side of a ledger. The explanation of this Contract turns on a point or Roman domestic manners， the systematic character and exceeding regularity of bookkeeping in ancient times. There are several minor difficulties of old Roman law， as， for example， the nature of the Slave''s Peculium， which are only cleared up when we recollect that a Roman household consisted or a number of persons strictly accountable to its head， and that every single item of domestic receipt and expenditure， after being entered in waste books， was transferred at stated periods to a general household ledger. There are some obscurities， however， in the descriptions we have received of the Literal Contract， the fact being that the habit of keeping books ceased to be universal in later times， and the expression “Literal Contract” came to signify a form of engagement entirely different from that originally understood. We are not， therefore， in a position to say， with respect to the primitive Literal Contract， whether the obligation was created by a simple entry on the part of the creditor， or whether the consent of the debtor or a corresponding entry in his own books was necessary to give it legal effect. The essential point is however established that， in the case of this Contract， all formalities were dispensed with on a condition being complied with. This is another step downwards in the history of contract-law.

　　The Contract which stands next in historical succession， the Real Contract， shows a great advance in ethical conceptions. Whenever any agreement had for its object the deliver of a specific thing —— and this is the case with the large majority of simple engagements —— the Obligation was drawn down as soon as the delivery had actually taken place. Such a result must have involved a serious innovation on the oldest ideas of Contract； for doubtless， in the primitive times， when a Contracting party had neglected to clothe his agreement in a stipulation， nothing done in pursuance of the agreement would be recognised by the law A person who had paid over money on loan would be unable to sue for its repayment unless he had formally stipulated for it. But， in the Real Contract， performance on one side is allowed to impose a legal duty on the other —— evidently on ethical grounds. For the first time then moral considerations appear as an ingredient in Contract-law， and the Real Contract differs from its two predecessors in being rounded on these， rather than on respect for technical forms or on deference to Roman domestic habits.

　　We now reach the fourth class， or Consensual Contracts， the most interesting and important of all. Four specified Contracts were distinguished by this name： Mandatum， i.e. Commission or Agency； Societas or Partnership； Emtio Venditio or Sale； and Locatio Conductio or Letting and Hiring. A few pages ago， after stating that a Contract consisted of a Pact or Convention to which an Obligation had been superadded， I spoke of certain acts or formalities by which the law permitted the Obligation to be attracted to the Pact. I used this language on account of the advantage of a general expression， but it is not strictly correct unless it be understood to include the negative as well as the positive. For， in truth， the peculiarity of these Consensual Contracts is that no formalities are required to create them out of the Pact. Much that is indefensible， and much more that is obscure， has been written about the Consensual Contracts， and it has even been asserted that in them the consent of the Parties is more emphatically given than in any other species of agreement. But the term Consensual merely indicates that the Obligation is here annexed at once to the Consensus. The Consensus， or mutual assent of the parties， is the final and crowning ingredient in the Convention， and it is the special characteristic of agreements falling under one of the four heads of Sale， Partnership， Agency， and Hiring， that， as soon as the assent of the parties has supplied this ingredient， there is at once a Contract. The Consensus draws with it the Obligation， performing， in transactions of the sort specified， the exact functions which are discharged， in the other contracts， by the Res or Thing， by the Verba stipulationis， and by the Literae or written entry in a ledger. Consensual is therefore a term which does not involve the slightest anomaly， but is exactly analogous to Real， Verbal， and Literal.

　　In the intercourse of life the commonest and most important of all the contracts are unquestionably the four styled Consensual. The larger part of the collective existence of every community is consumed in transactions of buying and selling， of letting and hiring， of alliances between men for purposes of business， of delegation of business from one man to another； and this is no doubt the consideration which led the Romans， as it has led most societies， to relieve these transactions from technical incumbrance， to abstain as much as possible from clogging the most efficient springs of social movement. Such motives were not of course confined to Rome， and the commerce of the Romans with their neighbours must have given them abundant opportunities for observing that the contracts before us tended everywhere to become Consensual， obligatory on the mere signification of mutual assent. Hence， following their usual practice， they distinguished these contracts as contracts Juris Gentium. Yet I do not think that they were so named at a very early period. The first notions of a Jus Gentium may have been deposited in the minds of the Roman lawyers long before the appointment of a Praetor Peregrinus， but it would only be through extensive and regular trade that they would be familiarised with the contractual system of other Italian communities， and such a trade would scarcely attain considerable proportions before Italy had been thoroughly pacified， and the supremacy of Rome conclusively assured. Although， however， there is strong probability that the Consensual Contracts were the latest-born into the Roman system， and though it is likely that the qualification， Juris Gentium， stamps the recency of their origin， yet this very expression， which attributes them to the “Law of Nations，” has in modern times produced the notion of their extreme antiquity. For， when the “Law of Nations” had been converted into the “Law of Nature，” it seemed to be implied that the Consensual Contracts were the type of the agreements most congenial to the natural state； and hence arose the singular belief that the younger the civilisation， the simpler must be its forms of contract.

　　The Consensual Contracts， it will be observed， were extremely limited in number. But it cannot be doubted that they constituted the stage in the history of Contract-law from which all modern conceptions of contract took their start. The motion of the will which constitutes agreement was now completely insulated， and became the subject of separate contemplation； forms were entirely eliminated from the notion of contract， and external acts were only regarded as symbols of the internal act of volition. The Consensual Contracts had， moreover， been classed in the Jus Gentium， and it was not long before this classification drew with it the inference that they were the species of agreement which represented the engagements approved of by Nature and included in her code. This point once reached， we are prepared for several celebrated doctrines and distinctions of the Roman lawyers. One of them is the distinction between Natural and Civil Obligations. When a person of full intellectual maturity had deliberately bound himself by an engagement， he was said to be under a natural obligation， even though he had omitted some necessary formality， and even though through some technical impediment he was devoid of the formal capacity for making a valid contract. The law （and this is what the distinction implies） would not enforce the obligation， but it did not absolutely refuse to recognise it； and natural obligations differed in many respects from obligations which were merely null and void， more particularly in the circumstance that they could be civilly confirmed， if the capacity for contract were subsequently acquired. Another very peculiar doctrine of the jurisconsults could not have had its origin earlier than the period at which the Convention was severed from the technical ingredients of Contract. They taught that though nothing but a Contract could be the foundation of an action， a mere Pact or Convention could be the basis of a plea. It followed from this， that though nobody could sue upon an agreement which he had not taken the precaution to mature into a Contract by complying with the proper forms， nevertheless a claim arising out of a valid contract could be rebutted by proving a counter agreement which had never got beyond the state of a simple convention. An action for the recovery of a debt could be met by showing a mere informal agreement to waive or postpone the payment.

　　The doctrine just stated indicates the hesitation of the Praetors in making their advances towards the greatest of their innovations. Their theory of Natural law must have led them to look with especial favour on the Consensual Contracts and on those Pacts or Conventions of which the Consensual Contracts were only particular instances； but they did not at once venture on extending to all Conventions the liberty of the Consensual Contracts. They took advantage of that special superintendence over procedure which had been confided to them since the first beginnings of Roman law， and， while they still declined to permit a suit to be launched which was not based on a formal contract， they gave full play to their new theory of agreement in directing the ulterior stages of the proceeding. But， when they had proceeded thus far， it was inevitable that they should proceed farther. The revolution of the ancient law of Contract was consummated when the Praetor of some one year announced in his Edict that he would grant equitable actions upon Pacts which had never been matured at all into Contracts， provided only that the Pacts in question had been founded on a consideration （causa）。 Pacts of this sort are always enforced under the advanced Roman jurisprudence. The principle is merely the principle of the Consensual. Contract carried to its proper consequence； and， in fact， if the technical language of the Romans had been as plastic as their legal theories， these Pacts enforced by the Praetor would have been styled new Contracts， new Consensual Contracts. Legal phraseology is， however， the part of the law which is the last to alter， and the Pacts equitably enforced continued to be designated simply Praetorian Pacts. It will be remarked that unless there were consideration for the Pact， it would continue nude so far as the new jurisprudence was concerned； in order to give it effect， it would be necessary to convert it by a stipulation into a Verbal Contract.

　　The extreme importance of this history of Contract， as a safeguard against almost innumerable delusions， must be my justification for discussing it at so considerable a length. It gives a complete account of the march of ideas from one great landmark of jurisprudence to another. We begin with Nexum， in which a Contract and a Conveyance are blended， and in which the formalities which accompany the agreement are even more important than the agreement itself. from the Nexum we pass to the Stipulation， which is a simplified form of the older ceremonial. The Literal Contract comes next， and here all formalities are waived， if proof of the agreement can be supplied from the rigid observances of a Roman household. In the Real Contract a moral duty is for the first time recognised， and persons who have joined or acquiesced in the partial performance of an engagement are forbidden to repudiate it on account of defects in form. Lastly， the Consensual Contracts emerge， in which the mental attitude of the contractors is solely regarded， and external circumstances have no title to notice except as evidence of the inward undertaking. It is of course uncertain how far this progress of Roman ideas from a gross to a refined conception exemplifies the necessary progress of human thought on the subject of Contract. The Contract-law of all other ancient societies but the Roman is either too scanty to furnish information， or else is entirely lost； and modern jurisprudence is so thoroughly leavened with the Roman notions that it furnishes us with no contrasts or parallels from which instruction can be gleaned. from the absence， however，。 the of everything violent， marvellous， or unintelligible in changes I have described， it may be reasonably believed that the history of ancient Roman Contracts is， up to a certain point， typical of the history of this class of legal conceptions in other ancient societies. But it is only up to a certain point that the progress of Roman law can be taken to represent the progress of other systems of jurisprudence. The theory of Natural law is exclusively Roman. The notion of the vinculum juris， so far as my knowledge extends， is exclusively Roman. The many peculiarities of the mature Roman law of Contract and Delict which are traceable to these two ideas， whether singly or in combination， are therefore among the exclusive products of one particular society. These later legal conceptions are important， not because they typify the necessary results of advancing thought under all conditions， but because they have exercised perfectly enormous influence on the intellectual diathesis of the modern world.

　　I know nothing more wonderful than the variety of sciences to which Roman law， Roman Contract-law more particularly， has contributed modes of thought， courses of reasoning， and a technical language. Of the subjects which have whetted the intellectual appetite of the moderns， there is scarcely one， except Physic， which has not been Altered through Roman jurisprudence. The science of pure Metaphysics had， indeed， rather a Greek than a Roman parentage， but Politics， Moral Philosophy， and even Theology found in Roman law not only a vehicle of expression， but a nidus in which some of their profoundest inquiries were nourished into maturity. For the purpose of accounting for this phenomenon， it is not absolutely necessary to discuss the mysterious relation between words and ideas， or to explain how it is that the human mind has never grappled with any subject of thought， unless it has been provided beforehand with a proper store of language and with an apparatus of appropriate logical methods. It is enough to remark， that， when the philosophical interests of the Eastern and Western worlds were separated， the founders of Western thought belonged to a society which spoke Latin and reflected in Latin. But in the Western provinces the only language which retained sufficient precision for philosophical purposes was the language of Roman law， which by a singular fortune had preserved nearly all the purity of the Augustan age， while vernacular Latin was degenerating into a dialect of portentous barbarism. And if Roman jurisprudence supplied the only means of exactness in speech， still more emphatically did it furnish the only means of exactness， subtlety， or depth in thought. For at least three centuries， philosophy and science were without a home in the West； and though metaphysic and metaphysical theology were engrossing the mental energies of multitudes of Roman subjects， the phraseology employed in these ardent inquiries was exclusively Greek， and their theatre was the Eastern half of the Empire. Sometimes， indeed， the conclusions of the Eastern disputants became so important that every man''s assent to them， or dissent from them， had to be recorded， and then the West was introduced to the results of Eastern controversy， which it generally acquiesced in without interest and without resistance. Meanwhile， one department of inquiry， difficult enough for the most laborious， deep enough for the most subtle， delicate enough for the most refined， had never lost its attractions for the educated classes of the Western provinces. To the cultivated citizen of Africa， of Spain， of Gaul and of Northern Italy it was jurisprudence， and jurisprudence only， which stood in the place of poetry and history， of philosophy and science. So far then from there being anything mysterious in the palpably legal complexion of the earliest efforts of Western thought it would rather be astonishing if it had assumed any other hue. I can only express my surprise at the scantiness of the attention which has been given to the difference between Western ideas and Eastern， between Western theology and Eastern， caused by the presence of a new ingredient. It is precisely because the influence of jurisprudence begins to be powerful that the foundation of Constantinople and the subsequent separation of the Western Empire from the Eastern， are epochs in philosophical history. But continental thinkers are doubtless less capable of appreciating the importance of this crisis by the very intimacy with which notions derived from Roman Law are mingled up with every day ideas. Englishmen， on the other hand， are blind to it through the monstrous ignorance to which they condemn themselves of the most plentiful source of the stream of modern knowledge， of the one intellectual result of the Roman civilisation. At the same time， an Englishman， who will be at the pains to familiarise himself with the classical Roman law is perhaps， from the very slightness of the interest which his countrymen have hitherto taken in the subject， a better judge than a Frenchman or a German of the value of the assertions I have ventured to make. Anybody who knows what Roman jurisprudence is， as actually practised by the Romans， and who will observe in what characteristic the earliest Western theology and philosophy differ from the phases of thought which preceded them， may be safely left to pronounce what was the new element which had begun to pervade and govern speculation.

　　The part of Roman law which has had most extensive influence on foreign subjects of inquiry has been the law of Obligation， or what comes nearly to the same thing， of Contract and Delict. The Romans themselves were not unaware of the offices which the copious and malleable terminology belonging to this part of their system might be made to discharge， and this is proved by their employment of the peculiar adjunct quasi in such expressions as Quasi-Contract and Quasi-Delict. “Quasi，” so used， is exclusively a term of classification. It has been usual with English critics to identify the Quasi-contracts with implied contracts， but this is an error， for implied contracts are true contracts， which quasi-contracts are not. In implied contracts， acts and circumstances are the symbols of the same ingredients which are symbolised， in express contracts， by words； and whether a man employs one set of symbols or the other must be a matter of indifference so far as concerns the theory of agreement. But a Quasi-Contract is not a contract at all. The commonest sample of the class is the relation subsisting between two persons one of whom has paid money to the other through mistake. The law， consulting the interests of morality， imposes an obligation on the receiver to refund， but the very nature of the transaction indicates that it is not a contract， inasmuch as the Convention， the most essential ingredient of Contract， is wanting. This word “quasi，” prefixed to a term of Roman law， implies that the conception to which it serves as an index is connected with the conception with which the comparison is instituted by a strong superficial analogy or resemblance. It does not denote that the two conceptions are the same or that they belong to the same genus. On the contrary， it negatives the notion of an identity between them； but it points out that they are sufficiently similar for one to be classed as the sequel to the other， and that the phraseology taken from one department of law may be transferred to the other and employed without violent straining in the statement of rules which would otherwise be imperfectly expressed.

　　It has been shrewdly remarked， that the confusion between Implied Contracts， which are true contracts， and Quasi Contracts， which are not contracts at all， has much in common with the famous error which attributed political rights and duties to an Original Compact between the governed and the governor. Long before this theory had clothed itself in definite shape， the phraseology of Roman contract-law had been largely drawn upon to describe that reciprocity of rights and duties which men had always conceived as existing between sovereigns and subjects. While the world was full of maxims setting forth with the utmost positiveness the claims of kings to implicit obedience —— maxims which pretended to have had their origin in the New Testament， but which were really derived from indelible recollections of the Cesarian despotism —— the consciousness of correlative rights possessed by the governed would have been entirely without the means of expression if the Roman law of Obligation had not supplied a language capable of shadowing forth an idea which was as yet imperfectly developed. The antagonism between the privileges of kings and their duties to their subjects was never， I believe， lost sight of since Western history began， but it had interest for few except speculative writers so long as feudalism continued in vigour， for feudalism effectually controlled by express customs the exorbitant theoretical pretensions of most European sovereigns. It is notorious， however， that as soon as the decay of the Feudal System had thrown the medieval constitutions out of working order， and when the Reformation had discredited the authority of the Pope， the doctrine of the divine right of Kings rose immediately into an importance which had never before attended it. The vogue which it obtained entailed still more constant resort to the phraseology of Roman law， and a controversy which had originally worn a theological aspect assumed more and more the air of a legal disputation. A phenomenon then appeared which has repeatedly shown itself in the history of opinion. Just when the argument for monarchical authority rounded itself into the definite doctrine of Filmer， the phraseology， borrowed from the Law of Contract， which had been used in defence of the rights of subjects， crystallised into the theory of an actual original compact between king and people， a theory which， first in English and afterwards， and more particularly， in French hands， expanded into a comprehensive explanation of all the phenomena of society and law. But the only real connection between political and legal science had consisted in the last giving to the first the benefit of its peculiarly plastic terminology. The Roman jurisprudence of Contract had performed for the relation of sovereign and subject precisely the same service which， in a humbler sphere， it rendered to the relation of person bound together by an obligation of “quasi-contract.” It had furnished a body of words and phrases which approximated with sufficient accuracy to the ideas which then were from time to time forming on the subject of political obligation. The doctrine of an Original Compact can never be put higher than it is placed by Dr. Whewell， when he suggests that， though unsound， “it may be a convenient form for the expression of moral truths.”

　　The extensive employment of legal language on political subjects previously to the invention of the Original Compact， and the powerful influence which that assumption has exercised subsequently， amply account for the plentifulness in political science of words and conceptions， which were the exclusive creation of Roman jurisprudence. Of their plentifulness in Moral Philosophy a rather different explanation must be given， inasmuch as ethical writings have laid Roman law under contribution much more directly than political speculations， and their authors have been much more conscious of the extent of their obligation. In speaking of moral philosophy as extraordinarily indebted to Roman jurisprudence， I must be understood to intend moral philosophy as understood previously to the break in its history effected by Kant， that is， as the science of the rules governing human conduct， of their proper interpretation and of the limitations to which they are subject. Since the rise of the Critical Philosophy， moral science has almost wholly lost its older meaning， and， except where it is preserved under a debased form in the casuistry still cultivated by Roman Catholic theologians， it seems to be regarded nearly universally as a branch of ontological inquiry. I do not know that there is a single contemporary English writer， with the exception of Dr. Whewell， who understands moral philosophy as it was understood before it was absorbed by metaphysics and before the groundwork of its rules came to be a more important consideration than the rules themselves. So long， however， as ethical science had to do with the practical regimen of conduct， it was more or less saturated with Roman law. Like all the great subjects of modern thought， it was originally incorporated with theology. The science of Moral Theology， as it was at first called， and as it is still designated by the Roman Catholic divines， was undoubtedly constructed， to the full knowledge of its authors， by takin principles of conduct from the system of the Church， and by using the language and methods of jurisprudence for their expression and expansion. While this process went on， it was inevitable that jurisprudence， though merely intended to be the vehicle of thought， should communicate its colour to the thought itself. The tinge received through contact with legal conceptions is perfectly perceptible in the earliest ethical literature of the modern world， and it is evident， I think， that the Law of Contract， based as it is on the complete reciprocity and indissoluble connection of rights and duties， has acted as a wholesome corrective to the predispositions of writers who， if left to themselves， might have exclusively viewed a moral obligation as the public duty of a citizen in the Civitas Dei. But the amount of Roman Law in moral theology becomes sensibly smaller at the time of its cultivation by the great Spanish moralists. Moral theology， developed by the juridical method of doctor commenting on doctor， provided itself with a phraseology of its own， and Aristotelian peculiarities of reasoning and expression， imbibed doubtless in great part from the Disputations on Morals in the academical schools， take the place of that special turn of thought and speech which can never be mistaken by any person conversant with the Roman law. If the credit of the Spanish school of moral theologians had continued， the juridical ingredient in ethical science would have been insignificant， but the use made of their conclusions by the next generation of Roman Catholic writers on these subjects almost entirely destroyed their influence. Moral Theology， degraded into Casuistry， lost all interest for the leaders of European speculation； and the new science of Moral Philosophy， which was entirely in the hands of the Protestants， swerved greatly aside from the path which the moral theologians had followed. The effect was vastly to increase the influence of Roman law on ethical inquiry.

　　“Shortly（1*） after the Reformation， we find two great schools of thought dividing this class of subjects between them. The most influential of the two was at first the sect of school known to us as the Casuists， all of them in spiritual communion with the Roman Catholic Church， and nearly all of them affiliated to one or other of her religious orders. On the other side were a body of writer connected with each other by a common intellectual descent from the great author of the treatise De Jure Belli et Pacis， Hugo Grotius. Almost all of the latter were adherents of the Reformation， and though it cannot be said that they were formally and avowedly at conflict with the Casuists， the origin and object of their system were nevertheless essentially different from those of Casuistry. It is necessary to call attention to this difference， because it involves the question of the influence of Roman law on that department of thought with which both systems are concerned. The book of Grotius， though it touches questions of pure Ethics in every page， and though it is the parent immediate or remote of innumerable volumes of formal morality， is not， as is well known， a professed treatise on Moral Philosophy； it is an attempt to determine the Law of Nature， or Natural Law. Now， without entering upon the question， whether the conception of a Law Natural be not exclusively a creation of the Roman jurisconsults， we may lay down that， even on the admission of Grotius himself， the dicta of the Roman jurisprudence as to what parts of known positive law must be taken to be parts of the Law of Nature， are， if not infallible， to be received at all events with the profoundest respect. Hence the system of Grotius is implicated with Roman law at its very foundation， and this connection rendered inevitable —— what the legal training of the writer would perhaps have entailed without it —— the free employment in every paragraph of technical phraseology， and of modes of reasoning， defining， and illustrating， which must sometimes conceal the sense， and almost always the force and cogency， of the argument from the reader who is unfamiliar with the sources whence they have been derived. On the other hand， Casuistry borrows little from Roman law， and the views of morality contended for have nothing whatever in common with the undertaking of Grotius. All that philosophy of right and wrong which has become famous， or infamous， under the name of Casuistry， had its origin in the