Christian August Crusius: Instruction to live reasonably - Art of fulfilling your goals

Having completed Crusius’ account of natural law - study of what we human beings must strive for - we still have a second part of his moral philosophy to deal with - study of prudence or the best means for achieving our goals. While natural law is meant to affect our use of will by making us choose best goals, study of prudence should affect our understanding.

Crusius notes that many particular arts also tell what are the best means for achieving some particular end, but such arts are not included in the general study of prudence. Furthermore, Crusius also won’t accept in this study means that are clear enough from common experience. The only thing left, then, Crusius says, is to look at means that can be derived from the nature of human soul and the principles of whole moral philosophy.

Crusius notes that the means we are discussing can be means either of private or public matters, which divides the study of prudence into two parts. In addition to these two parts, Crusius remarks, a third part should be added, which would universally look at general means for any goal whatsoever. This general part of the study of prudence is then further divided into two parts. First part would study the best ways how to apply a given means, while the second part would explain how we can find means in general for different goals.

Starting from the first part, Crusius notes that one should at first try to simplify one’s goals. For instance, if we have a complex goal to reach, we should try to analyse this goal into finer components that could be pursued more easily. Furthermore, Crusius lists various general methods for ensuring that a given goal is reached, such as finding many possible means for one goal. Finally, Crusius suggests that we should always consider whether the means we use for achieving one goal could be used at the same time for pursuit of a different goal.

The second part Crucius divides into three sections, first of which deals with ways to find means pertaining to understanding. Crusius explicitly mentions such capacities as a capacity to look at things and perceive conditions affecting the use of those things as means. Furthermore, Crusius mentions the capacity to gather experience and information from different sources.

The second section is then about means concerning will. Crusius lists, among other things, bravery, cheerful mind and good moral taste as those means. All of these had their own reasons why Crusius included them - bravery would let us continue to fulfill our actions, no matter what the circumstances, cheerful mind would let us ignore potential harms and good moral taste would let us pick quickly what is right and what is wrong.

The largest section is the one where Crusius deals with means concerning relations to other persons. Firstly, he notes that no matter how moral and prudent our actions are, they definitely should appear so in the eyes of other people. Thus, he says, our actions should look like we have chosen our goals with reason and not seem purposeless.

In addition to making others think highly of oneself, Crusius also suggests that one should acquire skills to know what others actually think. Partially, he notes that there are certain general rules to follow here, such as that people often believe only what they can perceive and that they believe things that accord with their own desires.

Beyond such general rules, Crusius thinks that we can learn to interpret an individual person’s mind. In case of ourselves, these readings might be certain, while with other people, Crusius admits, we can often know their mind only with probability. Still, he says, we can use introspection to learn the nature of the capacities of mind, and then draw analogies to other people’s minds.

Crusius draws very stringent limits to in what measure we can hope to know other people. Just like many other philosophers before him, Crusius notes that while physiognomy or study of human mind from mien and other bodily features is in principle a possible science, it is definitely a quite uncertain science - person’s taste can tell us more than his facial expression, Crusius suggests. Furthermore, unlike some Wolffians, Crusius thinks that what person says or does in a state of intoxication - or other similar abnormal state - does not tell what they think in ordinary life.

Finally, Crusius warns against trying to predict person’s future actions, even if we know what they have in their mind. He does not completely discard the possibility, but suggests that this is possible only in cases, where a person is wont to follow their inclinations and external impulses. Because of a possibility of a freely chosen action, Crusius notes, such deductions of future actions are always unreliable - a human being could always choose to act otherwise.