And there is much that is anticipatory of modern libertarian views in the psychological argument by which Carneades attempted at once to avoid the Epicurean identification of will with chance, and to prove the rationality of choice, undetermined by any external or antecedent necessity, as an explanation of human actions Xxviii.
Modern theories date from the 18th century, when the humanitarian movement began to teach the dignity of the individual and to emphasize his rationality and responsibility.
On the contrary, a belief that conduct necessarily results upon the presence of certain motives, and that upon the application of certain incentives, whether of pain or pleasure, upon the presence of certain stimuli whether in the shape of rewards or punishments, actions of a certain character will necessarily ensue, would seem to vindicate the rationality of ordinary penal legislation, if its aim be deterrent or reformatory, to a far greater extent than is possible upon the libertarian hypothesis.
But when such is the case, mankind has never failed in the long run to vindicate its claim to rationality by showing a readiness to give up the old belief whenever tangible evidence of its fallaciousness was forthcoming.
In carrying out this scientific procedure false steps will from time to time be made, which will have to be retraced, or rather amended; but the combination of experimental science with theory has elevated our presumption of the rationality of all natural processes, so far as we can apprehend them at all, into practical certainty; so that, though the mode of presentation of the results may vary from age to age, it is hardly conceivable that the essentials of the method are not of permanent validity.
The immanent rationality of this first form, in virtue of which at the stage when intelligence acts freely on the occasion of the datum supplied it recognizes continuity with its own self-conscious process, is what gives the dialectical type its meaning.
On the other, he assigned to vas with its insight into rationality too high a function with regard to the concrete in which the surd was present, a power to certify the truth of scientific principles.
For relatively short focal lengths a triple construction such as this is almost necessary in order to obtain an objective free from aberration of the 3rd order, and it might be thought at first that, given the closest attainable degree of rationality between the colour dispersions of the two glasses employed, which we will call crown and flint, it would be impossible to devise another form of triple objective, by retaining the same flint glass, but adopting two sorts of crown instead of only one, which would have its secondary spectrum very much further reduced.
Confidence that we are right, he would say, is in itself no proof that we are right: when God asks assent to the truth of a proposition in religion, he either shows us its intrinsic rationality by ordinary means, or he offers miraculous proof of the reality of which we need reasonable evidence.
This case well illustrates the much closer approach to strict rationality of dispersion which is obtainable by using two different sorts of glass for the two positive lenses, even when one of them has a higher dispersive power than the glass used for the negative lens.