¶ … Priori vs. A Posteriori An Analysis of Morality via A Priori and A Posterior Reasoning

As Thomas Reid indicates, the terms a priori and a posteriori have undergone a disignification in modern times: "Previously to Kant the terms a priori and a posteriori were, in a sense which descended from Aristotle, properly and usually employed, -- the former to denote a reasoning from cause to effect -- the latter, a reasoning from effect to cause" (762). However, Kant used the old terms but in a peculiarly new way and "a priori came…to be extended to any abstract reasoning from a given notion to the conditions which such notion involved" (Reid 762). Essentially, while construction of the notion demanded some sort of experiential observance, such arguments were not defined as a posteriori but as a priori. This paper will use the traditional definitions of a priori and a posteriori to show how morality may be established on an a priori foundation, but that a posteriori factors may also have an impact on questions regarding moral law. Ultimately, this paper argues that there is such a thing as objective moral law and that it can be deduced in the mind.

Defining Terms

Kant argues that "the true science of logic has eliminated all its a posteriori or empirical elements, and stands now rigorously pure and all incontrovertibly a priori" (31). However, Kant's assessment is not in agreement will all philosophers, and before approaching an answer to the question of whether morality can be established purely on an a priori foundation, one must of course define his terms.

Perhaps the simplest way to define these terms is thus: a posteriori refers to reasoning "that is directly based on observation and inductive generalization" (Palgrave 43). In other words, a posteriori reasoning follows experience. It is based on observation of data collected through the application of the senses and used to arrive at a scientific conclusion. A priori reasoning, on the other hand, precedes experience and is formulated in the mind by way of deduction. William Stanley Jevons writes that "there is a great advantage in a priori knowledge; we can often apply it in cases where experiment or observation would be difficult" (209). The example Jevons gives is of our ability to determine without experiment that a rock that is dropped will heat up when it hits the ground. This knowledge may be deduced in the mind without reference to direct experiential knowledge. With these terms defined thus, the question may now be addressed: how is morality established? Is it deduced in the mind or is it calculable by experience? The answer is, in a way, both.

A Priori vs. A Posteriori

William Turner writes that "we know the moral law not by inference, but by immediate intuition. This intuition is, as it were, the primum philosophicum. It takes the place of Descartes' primary intuition of his own thought. From it all the important truths of philosophy are deduced, the freedom of the will, the immortality of the soul, and the existence of God." What Turner states is that morality is thus established on an a priori foundation. The several examples of a priori reasoning The a priori reasoning is sometimes called deductive or ontological. Anselm, for example, devised his ontological argument to prove the existence of God. But Aquinas many centuries later based his arguments on a posteriori foundations -- foundations derived from experience.

However, what Patrick Toner states is that "it is necessary to employ a priori or deductive inference in order to arrive at a knowledge of [morality], and as it is impossible to develop the arguments for [morality] without some working notion of [moral law], it is necessary to some extent to anticipate the deductive stage and combine a priori with the a posteriori method." Thus, one sees that an argument may be made for both a priori and a posteriori foundations impacting the establishment of morality. One may arrive at an understanding of the moral law by way of a priori arguments, but it is not necessarily without some experience with the moral law, thus making the a posteriori foundation complimentary.

What this means, as philosophers through the ages have demonstrated, is that there is no one pure way to the establishment of the moral law. However, one thing that is essential is admitting the objective certainty of sufficient reason -- "an assumption upon which the value of the physical sciences and of human knowledge generally is based" (Toner). As Patrick Toner indicates,...

If there is no objective validity, then "the whole process of human reasoning [may be] declared fallacious" (Toner). The example that Toner uses to support this argument is that "it is impossible to prove the principle of causality, just as it is impossible to prove the principle of contradiction; but it is not difficult to see that if the former is denied the latter may also be denied." Essentially, Toner suggests that the moral law is objective, because were it not so it would not be possible to form an idea of universal morality -- of the "uncaused cause." Yet, the idea of an "uncaused cause," whether named the Ego, the Will, the Unconscious, the Unknown, or the Absolute, is virtually admitted by all philosophers and so points to an objective reality that simply goes by many names and from which is derived varying deductions.
Thus, with this in mind, one may assert that there is such a thing as the objective moral law. Even if it is experienced subjectively, such experience does not take away or refute the objective reality that causes the effect. One has a conscience and one may deduce moral effects from moral causes, implying the existence of objective morality. Yet this distinction may be confused in modern times, especially since, as Thomas Reid states, "Kant contorted the term Category from its proper meaning of attribution; and from an objective to a subjective application; bestowing this name on the ultimate and necessary laws by which thought is governed in its manifestations" (762). Thus, one sees that there is a difference in philosophic and scholarly opinion regarding the very essence of the point -- whether objective reality is knowable, or whether truth as identity between intellect and reality is attainable. Kant's definition has "found acceptance; and been extended to designate, in general, all the a priori phenomena of mind" (Reid 762). But one is not constrained to accept such extensions. On the contrary, to formulate true statements, one is bound to resist them.

The Moral Law as Objective Reality and the Problem of Kant

One is no less bound to resist them in order to arrive at conclusions regarding moral law. The existence of the moral law, for instance, "implies the existence of God" -- through the law, which "implies a lawgiver," and through the implication "that there be somewhere a good which is not only supreme, but complete…This supreme good is God" (Turner). Yet, such conclusions are only capable of being derived if one first admits that objective reality is knowable as it exists outside the mind and that truth (as identity between intellect and reality) may be formulated in statements. To this end, Kant has much to say.

As Turner states, Kant's philosophical perspective is dubitable because, while it possesses great synthetic powers, it lacks analytic quality -- thus situating him as a path of divergence from the traditional philosophical mold. Indeed, Turner writes that

Not all are agreed as to Kant's rank among philosophers. Some rate his contributions to philosophy so highly that they consider his doctrines to be the culmination of all that went before him. Others, on the contrary, consider that he made a false start when he assumed in his criticism of speculative reason that whatever is universal and necessary in our knowledge must come from the mind itself, and not from the world of reality outside us.

In other words, if one is to abide by Kant's doctrines, he must argue that Aristotelian analytic judgments "do not advance knowledge at all, since they always 'remain within the concepts [subject and predicate] and make no advance beyond the data of the concepts'" (Turner). Kant's assertion is that Aristotelian philosophy is inadequate and compromising, since it is not built upon a purely a priori foundation. Kant wished to derive a kind of synthetic a priori system of reasoning -- in which analysis moved beyond the concept. However, according to Turner, Kant's system is flawed because "the so-called synthetic a priori judgments are all analytic" -- or, in other words, are the result of taking apart, not putting together.

Still, the moral law may certainly be said to be objective when one considers that it is knowable both by a priori and a posteriori reasoning. One need not be trapped either entirely in one's head or entirely…