dus, Bartholomæus, Ranulphus Higdenus, and, most famous of all, Joannes de Burgo. In the fifteenth century Gerson's famous Opus culum Tripartitum enjoyed the greatest reputation. St. Bernardine of Siena, St. John Capistran, and St. Antoninus also wrote on moral subjects. But the one who has exercised the widest influence is, of course, St. Thomas Aquinas (1227-74), who in his Secunda Secunda treats of moral theology in its organic connection with dogma. Its technical character, however, makes it somewhat unavailable as a manual for common use. Making this science practical was the achievement of the sixteenth century. The extraordinary development of this particular branch of theological knowledge was largely due to the doctrine of Probabilism.

This was not a new doctrine, but it was inaugurated as a system by a Spanish Dominican named Medina. The theory may be thus stated: A man in doubt about the lawfulness of an act has solid reasons for thinking it is lawful. These reasons may be intrinsic to the matter itself, or extrinsic, namely, the authority of some respectable theologian. But there may be contrary reasons of equal or greater weight than those in favor of it. Which course is he to elect? Probabilism teaches that he is free to do as he chooses, provided his reasons for acting be genuine and solid. He proceeds on the principle that, as the law is not certain, he is free; for no one is bound by a doubtful obligation. This liberty, however, is restricted if for some major obligation he is bound to take every reasonable means to achieve a certain object. A hunter may not discharge his rifle where it is merely probable no one will be hit; he must take every reasonable precaution; a Catholic priest may not act on the doctrine of probability where there is question of the validity of a sacrament. But apart from these antecedent obligations of justice, charity, and religion, Probabilism leaves a man free when he has good reasons for judging that he is doing right.

In the development of this casuistry four schools arose: the Tutiorists or Rigorists, who were either absolute or mitigated the former requiring absolute certainty, the latter the greatest probability; the Probabiliorists, who taught that in cases of doubt a man should always follow the safer course; the Equiprobabilists, who allowed liberty of action only when the reasons pro and con were evenly balanced, but modified that concession by saying that when the existence of the law was certain or even more probable, there could be no liberty against it, for the law being certainly or more probably in possession exacted fulfillment; the Laxists, who contended that one is free to act if he has even a slight reason to conclude that he is in the right. The Laxists were condemned by Innocent XI, and the Absolute Tutiorists by Alexander VII.

On these lines a fierce and protracted theological battle began, which finally narrowed down to a contest between the Probabiliorists and the Probabilists. From 1580 to 1650 Probabilism held possession. After that a reaction set in, and Probabiliorism was the favorite doctrine. At present the conditions have reverted to what they were in the beginning, and Probabilism almost everywhere prevails in the Roman Catholic church. The chief exponents are St. Alphonsus Liguori, Scavini, Gury, and Ballerini. The acrimony of these debates gave rise to

the odious significations which have been affixed to the word "casuistry." After the accusations of the Jansenists (see PASCAL; JANSENISM) ceased, about the middle of the eighteenth century, many Protestant writers took them up and denounced the casuistry of Probabilism as lax, equivocating, permitting the most detestable crimes, and outraging the most sacred obligations. These charges, no longer seriously made by intelligent students, have given rise to the secondary meaning of the word "casuistry" as, according to some, a method of oversubtle, sophistical, and dishonest reasoning for the purpose of evading the law; others regard it as an elimination of individual reason and conscience and a blind submission to authority. Consult: Döllinger and Reusch, Moralstreitigkeiten im siebzehnten Jahrhundert (1889); Slater, Cases of Conscience for English-Speaking Countries (New York, 1911); also works on Ethics under ETHICS. See PROBABILISM.

CA'SUS BELLI (Lat., case of war). The ground alleged by one power to justify its going to war with another. The grounds which in international law are recognized as affording a justification for war are: (a) the defense of the sovereignty and independence of the state; (b) the redress of grave injuries inflicted by a foreign power on the citizens of a state; (c) to obtain satisfaction for violations of the honor of a state, as for insults to its flag or its ambassadors; (d) the enforcement in serious cases of treaty obligations; (e) the prevention of threatened or intended injury, as a sudden disturbance of the balance of power in Europe, or the disregard by a European power of the Monroe Doctrine of the United States; (f) in rare cases, the prevention of flagrant wrong against religion or liberty, or grave oppression of a colony or weaker state, as in the war of the United States against Spain for the liberation of Cuba. (See INTERVENTION.) The most frequent cause of war, the desire of a state to further its own interests, is not recognized by international law as a legitimate casus belli. The humane tendencies of modern international law seek to restrict the causes for war, and by moral pressure to induce an offended state patiently to seek every other means of effecting its object before resorting to the dire expedient of war. See INTERNATIONAL LAW; HAGUE PEACE CONFERENCE; WAB, and the authorities there referred to.

CASWELL, kǎz'wel, ALEXIS (1799-1877). An American educator. He was born in Taunton, Mass., graduated at Brown University in 1822, and entered the Baptist ministry. He was professor of mathematics and natural philosophy in Brown University from 1828 to 1850 and of mathematics and astronomy from 1850 to 1864 and was president of that institution from 1868 to 1872. He was, besides, one of the founders of the American Association for the Advancement of Science. Besides a Life of Francis Wayland and a Textbook on Astronomy, he published several papers on meteorology in the Reports of the Smithsonian Institution and a Memorial of John Barstow (1864).

CASWELL, RICHARD (1729-89). A patriot soldier of the American Revolution and the first Governor of the State of North Carolina. He was born in Maryland, emigrated to North Carolina in 1746, studied and practiced law, and soon became prominent in Colonial politics. He was a member of the Colonial Assembly from

it down to the second phalanx and holds it in place without any conscious effort. From the lower (proximal) end of this claw bone a powerful flexor tendon runs back beneath the bones of the toe to the leg muscles, the contraction of which pulls the claw down with a circular motion which drives it and hooks it into the flesh, where it will tear loose before it will let go. Such

a

b

MECHANISM OF CAT'S CLAWS.

a, Toe at rest (claw sheathed); b, toe in action (claw thrown forward). The illustration shows the elastic ligament which passes from above the root of the claw downward and backward to the distal part of the second phalanx; also the long flexor tendon (which by being pulled backward draws down the claw) passing through the ligamentous loop attached to the under surface of the middle phalanx. The sesamoid bone beneath the distal end of the metacarpal is also shown. (After Mivart.)

is the mechanism of the action so familiar and effective in the cat when she is angry and "shows her claws." The cheeta (q.v.) lacks this power, and correspondingly its predatory habits partake of much that characterizes dogs.

Cats are mainly nocturnal in their habits, and the pupils of their eyes, which, as a rule, are vertically linear, are capable of great expansion and contraction, according to the light about them; the lion, however, by virtue of his fearlessness and circumstances generally, is mainly diurnal and has round pupils. The eyesight is good, but at night is supplemented by the highly sensitive feelers (vibrissa), long hairs projecting from the muzzle and above the eyes, each springing from a follicle from which a special nerve communicates with the brain. The sense of smell, though fairly developed, is inferior to that of dogs and various other animals. The hearing, however, is exceedingly sharp, the resonance of the sound being increased by the great size of the auditory bulla.

Cats are clothed in soft and usually rather long fur, longest in those, such as the ounce, or snow leopard, which live in cold regions, and shortest in the desert species, especially in the lion, which is further distinguished by a mane in the male sex. Little difference, as a rule, obtains between the sexes in size or appearance; but the kittens are often unlike their parents. Their pelts have never entered largely into the fur trade, however, except in the form of tiger-skin floor rugs, etc. The colors are mainly dark, with a prevalence of reddish or yellowish, and there is a universal and strong tendency towards spottedness (of which striping is another form), the young showing it even where the adult is concolorous, as in the lion, puma, eyra, etc. Arguments have been freely adduced for the value of this coloration in making the cats unnoticeable, but when it is learned that species almost oppositely colored and

marked live and hunt under identical circumstances with apparently equal success, the force of the speculation is seriously diminished.

Cats are not gregarious or coöperative, but live and hunt alone or in family parties; all are monogamous except the lion; and the reputation which some have for permanent mating is probably deserved only when an annual change of mate is impracticable because of scarcity or competition. They inhabit dens and lairs among rocks, in hollow trees, or dense thickets, without any special preparation, and the number of kittens does not usually exceed two in the large forms, but in the small species may be three, four, or five. These are usually born in the late spring of temperate latitudes or at the opening of the dry season in the tropics; and they remain under the guidance of the mother until nearly full-grown. Though many species are widely distributed, none are migratory, and few wander far, the tiger and leopard being the most inclined, perhaps, to wide ranging. The disposition of most cats is to remain near a settled lair-a disposition recognizable in the attachment to the house and to a favorite corner that distinguishes our house cats and makes them loath to change their location and customs. A certain inflexibility seems to characterize their minds, and the secrecy, noiseless stealth, patience, and ruthlessness which belong to their methods of life in the forest have affected their temperaments. The needful savagery of their nature is ingrained and as a rule unyielding to gentler influences in changed conditions. Hence they are, as a class, untamable, the very few exceptions having become the stock of the domesticated races. Most species can be made friendly to man only when kittens, asserting their feral natures and becoming untrustworthy as soon as growth brings sense of power and predacious instincts. Trainers have subjugated certain species, but they are kept in subjection by fear alone and make their performance unwillingly and without pride or joy in it. A few have been trained to hunt, but none to retrieve, and in general they approach sympathy with man and the attitude of companion and helper far less than dogs, which exceed them in certain directions of intelligence, as, for example, the understanding of mechanical appliances. A cat's expression of its emotions is mainly by "lashing" of the tail or a trembling of its tip, when excited; by spitting, yowls, and screams when very angry or sexually excited; by plaintive mewings when in trouble or desiring notice; and by a vibrating murmur deep in its throat (purring) when satisfied or contented. position of the ears is very significant, as in most other animals; and the arching of the back, erection of the hair, and elevation of the tail, so familiar in our house cats, which thus try to make themselves look as large and terrible as possible in the presence of an enemy, are characteristic of all the smaller forms, though little indulged by the greater kinds. The relation of the cats to mankind generally is one of enmity-they are neighbors dangerous to him or his domestic animals which must be got rid of wherever civilization is to prevail. Hence they have mostly disappeared from thickly settled regions. The lion and tiger were inhabitants of Europe within historic times, but neither is now to be found near the Mediterranean on either side; and even the wild cat is rare in Europe,

The