Descartes's Conceptual Distinction and its Ontological Import

Abstract

Descartes' conceptual distinction (or distinctio rationis) is commonly understood to be a distinction created by the mind's activity without a foundation in re. This paper challenges this understanding partially based on a letter to an unknown correspondent in which Descartes claims not to admit distinctions without a foundation. He goes on to claim that his conceptual distinction is not a distinctio rationis ratiocinantis (i.e. a distinction of reasoning reason) but is something like a formal distinction or, more precisely, a distinctio ! rationis ratiocinatae (i.e. a distinction of reasoned reason). This remark is then explored through Descartes' other writings and his scholastic intellectual heritage. I conclude that Descartes' conceptual distinction just is a formal distinction understood as a distinctio rationis ratiocinatae as expressed in the works of Scotus, Suarez and Eustachius, and so it has a foundation in re in very much the same way as a formal distinction.

Malebranche on Intelligible Extension: A Programmatic Interpretation

“…We 6 Another way to put this is that no real distinction can be made between any two of God's "parts"e. g. among the Father, the Son, and the Holy Spirit. For a critical discussion of this concept within Cartesian philosophy generally, see Hoffman (2002); Skirry (2004); & Rozemond (2011). 7 I have detailed, anyway, what I take to be the most important dialectical exchanges between Malebranche and his critics on this point.…”

The Duck's Leg: Descartes's Intermediate Distinction

“…Included in the latter category was Scotus's formal distinction, which Descartes assumed (falsely) was no different from the modal distinction 3 . In the hastily written but informative letter to an unknown correspondent of 1645 or 1646, Descartes conflates the distinction rationis ratiocinatae (of reasoned reason) with the formal distinction, which has been taken by some as a sign of Descartes's perhaps increased familiarity with debates among the Jesuits about Scotus's formal distinction (Clemenson 2007, unpublished typescript; Skirry 2004). By itself, Descartes's clarification in the letter of 1645 or 1646 fails to illuminate the terms of the distinction rationis ratiocinatae in any definitive way, not least of all because of the confusion among the Jesuits about how the formal distinction was to be understood.…”

“…But this reading struggles with passages from Descartes's texts which suggest that the extremes of a distinction of (reasoned) reason are in things and not merely modes of thought. Although Descartes refers to duration, order, and number as “modes under which we consider things,” they are referred to as not separate from the things numbered, ordered, or having duration ( Principles , I, 55; AT, 8A, 26; Hoffman 2002, 61–2; Skirry 2004, 136). Hoffman (2002, 62) notes that in other passages, Descartes draws a distinction between attributes that are in things, such as duration, and those that are merely in thought, such as time, which is simply the measure of motion ( Principles , I, 57; AT, 8A, 27).…”

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If some but not all that pertains to the understanding of y can be excluded from the understanding of x, but nothing that pertains to the understanding of x can be excluded from the understanding of y, then x is only conceptually distinct from substance y. (Skirry 2004, 125)

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