Chapter 8, Footnote #01
Intentional vs. Voluntary/Involuntary
On this occasion the words voluntary and involuntary are commonly employed. These, however, I purposely abstain from, on account of the extreme ambiguity of their signification. By a voluntary act is meant sometimes, any act, in the performance of which the will has had any concern at all; in this sense it is synonymous to intentional: sometimes such acts only, in the production of which the will has been determined by motives not of a painful nature; in this sense it is synonymous to unconstrained, or uncoerced: sometimes such acts only, in the production of which the will has been determined by motives, which, whether of the pleasurable or painful kind, occurred to a man himself, without being suggested by any body else; in this sense it is synonymous to spontaneous. The sense of the word involuntary does not correspond completely to that of the word voluntary. Involuntary is used in opposition to intentional and to unconstrained: but not to spontaneous. It might be of use to confine the signification of the words voluntary and involuntary to one single and very narrow case, which will be mentioned in the next note.