  The much augmented second edition of Jacobi’s first major work included a fuller documentation of the correspondence with Mendelssohn, and eight new supplements in which, among other things, Jacobi offered a more detailed exposition of Spinoza’s philosophy (Supplements VI, VII) and a lengthy criticism of Herder’s version of Spinozism (Supplement IV). It was also prefaced with fifty-two propositions — twenty-three purporting to defend the thesis ‘Man does not have Freedom’; the remaining twenty-nine, the opposite thesis ‘Man has Freedom’. The argument in defence of the first thesis is based on the assumption that human affairs are organized mechanistically, i.e. according to a concatenation of purely efficient causes that would make the being of each totally dependent on the external being of everything else. In defending the thesis Jacobi follows Spinoza closely. The mechanism at issue applies to the cognitive side of man just as much as to his bodily side.  Consciousness, or representational being, is only a mirror of extended being. Whatever happens in the latter is repeated on the side of thought, though according to thought’s own modality of existence. Thus, according to Jacobi, syllogistic thinking is mechanistic in nature, being driven by principles ab ante no less than any corporeal sequence of events. So far as the opposing thesis is concerned, Jacobi argues for it by retrieving a theme from the David Hume. If it is the case that a finite ‘I’ acquires identity only when confronted by an equally finite ‘Thou’, then, just as for the required interplay between the two one must assume on each side a source of ‘passivity’ that allows each to be limited by the other, so one must also equally assume in them a countervailing source of ‘activity’. This source is irreducible. It follows that ‘activity’ and ‘passivity’ must be assumed to run across the world we know in every part of it. In some parts, the one element might well display a greater degree of intensity than the other; nowhere, however, can either element crowd out the other totally. It also follows that, though mechanism is both possible and necessary, a totally mechanistic organization of things that would eo ipso allow no room for individual freedom, i.e. one that would reduce all things to external relations, is an impossibility, for it would in fact reduce things to mere nothingness (Jacobi, 1789: xxxv-xxxvi). It would make them totally passive. ‘Passivity’, however, has no meaning except in relation to ‘activity’. The conceptual basis for denying the reality of individually attributable human act is thus removed.