[27] Some further consideration of this question will be found in a subsequent chapter. Cf. Book iv. chap. iv. § 2.
§ 1. In the first chapter I spoke of actions that we judge to be right and what ought to be done as being “reasonable,” or “rational,” and similarly of ultimate ends as “prescribed by Reason”: and I contrasted the motive to action supplied by the recognition of such reasonableness with “non-rational” desires and inclinations. This manner of speaking is employed by writers of different schools, and seems in accordance with the common view and language on the subject. For we commonly think that wrong conduct is essentially irrational, and can be shown to be so by argument; and though we do not conceive that it is by reason alone that men are influenced to act rightly, we still hold that appeals to the reason are an essential part of all moral persuasion, and that part which concerns the moralist or moral philosopher as distinct from the preacher or moral rhetorician. On the other hand it is widely maintained that, as Hume says, “Reason, meaning the judgment of truth and falsehood, can never of itself be any motive to the Will”; and that the motive to action is in all cases some Non-rational Desire, including under this term the impulses to action given by present pleasure and pain. It seems desirable to examine with some care the grounds of this contention before we proceed any further.
Let us begin by defining the issue raised as clearly as possible. Every one, I suppose, has had experience of what is meant by the conflict of non-rational or irrational desires with reason: most of us (_e.g._) occasionally feel bodily appetite prompting us to indulgences which we judge to be imprudent, and anger prompting us to acts which we disapprove as unjust or unkind. It is when this conflict occurs that the desires are said to be irrational, as impelling us to volitions opposed to our deliberate judgments; sometimes we yield to such seductive impulses, and sometimes not; and it is perhaps when we do _not_ yield that the impulsive force of such irrational desires is most definitely felt, as we have to exert in resisting them a voluntary effort somewhat analogous to that involved in any muscular exertion. Often, again,--since we are not always thinking either of our duty or of our interest,--desires of this kind take effect in voluntary actions without our having judged such actions to be either right or wrong, either prudent or imprudent; as (_e.g._) when an ordinary healthy man eats his dinner. In such cases it seems most appropriate to call the desires “non-rational” rather than “irrational.” Neither term is intended to imply that the desires spoken of--or at least the more important of them--are not normally accompanied by intellectual processes. It is true that some impulses to action seem to take effect, as we say “blindly” or “instinctively,” without any definite consciousness either of the end at which the action is aimed, or of the means by which the end is to be attained: but this, I conceive, is only the case with impulses that do not occupy consciousness for an appreciable time, and ordinarily do not require any but very familiar and habitual actions for the attainment of their proximate ends. In all other cases--that is, in the case of the actions with which we are chiefly concerned in ethical discussion--the result aimed at, and some part at least of the means by which it is to be realised, are more or less distinctly represented in consciousness, previous to the volition that initiates the movements tending to its realisation. Hence the resultant forces of what I call “non-rational” desires, and the volitions to which they prompt, are continually modified by intellectual processes in two distinct ways; first by new perceptions or representations of means conducive to the desired ends, and secondly by new presentations or representations of facts actually existing or in prospect--especially more or less probable consequences of contemplated actions--which rouse new impulses of desire and aversion.