Psychologia Empirica

I remember having warned of this myself. However, these things will be understood more clearly when we have provided a system of moral philosophy deduced a priori from psychological principles.

§. 9.

Use in Logic.

Empirical psychology provides principles for Logic. We have already provided a demonstration when we showed which principles Logic possesses (§. 89 Disc. prælim.): see it, therefore, in that same place.

Certainly, if you wish to provide an a priori account of logical rules, it is necessary to have recourse to those things which are handed down in Psychology concerning the faculty of cognition. For this reason, also, when we were about to provide a Logic using the demonstrative method, we treated of the three operations of the mind, the formal difference of notions, and the use of terms, which have their proper place in empirical psychology; and here and there throughout that work you will discover principles borrowed from empirical psychology. You will find, therefore, that the more deeply you have investigated the human mind in Psychology, the more abundant light is shed upon Logic. Many other things could well be said about the utility of empirical psychology, but these may suffice to persuade those for whom the certain knowledge of God and of oneself, as well as the study of virtue, is a care and a concern, of the cultivation of Psychology. And to that end, I was pleased to repeat some things which could be presupposed from the Preliminary Discourse.

§. 10.

The pleasure of psychological study.

The study of empirical psychology suffuses the mind eager for knowledge with much pleasure, and renders it capable of a pleasure which otherwise would not fall to it. For empirical psychology teaches those things which occur in our soul while we are conscious of them (§. 2). Therefore, since a mind eager for knowledge perceives pleasure from acquired cognition, it ought especially to perceive pleasure from the knowledge of itself; consequently, since the knowledge of the soul acquired from empirical psychology is certain (§. 567 Log.), it ought to perceive pleasure from psychological study.

Since in empirical psychology we know the principles from which an account of those things that occur in the human soul is provided (§. 1), and indeed the account of those things which are inherent in a being, or can be inherent in it, from the very