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Lotze, Rudolph Hermann (1817–81)

DOI
10.4324/9780415249126-DC049-1
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DOI: 10.4324/9780415249126-DC049-1
Version: v1,  Published online: 1998
Retrieved March 29, 2024, from https://www.rep.routledge.com/articles/biographical/lotze-rudolph-hermann-1817-81/v-1

2. Logic

The first book of the first volume of Lotze’s System begins with ‘pure logic’. He starts by affirming that our mental life – the ‘current of ideas’ – essentially involves ‘connection’: ideas appear in relations of succession or simultaneity. But does this connection denote real coherence or mere coincidence? That is, are the associative connections found in the current of ideas sufficient for objective knowledge or indicative only of subjective error and illusion? Lotze concludes that coherence is distinguished from mere conjunction only by reference to a ground (or basis) for such coherence. And this investigation is the province of ‘thought’ proper.

Hence to logic, and not to psychology, belongs the discovery of the bases of justification. The dog can associate the raised stick (in the hand of its master) with pain, but only human thought can relate the identical matter in inferential terms, in virtue of logical consequence. The peculiar nature of thought thus lies in the supplement that it provides over and above the mere current of ideas: the addition of a justificatory ground (or rationale) for the connection. This, in turn, depends critically upon the capacity of thought to impose logical form. To provide for a firm structure of truth, it must arrange its building stones precisely. This foundation must, further, be of a form suitable for thought; so there must exist some process by which thought logically apprehends the sensory manifold.

Lotze believed that concept-formation belongs to thought proper and not to the psychological processes of abstraction or synthesis. This principle is to be established by a careful determination of the different stages involved in the refining of ideation into thought. The first step in the creation of logical building stones is the conversion of ‘impressions’ into ‘ideas’. This takes place by naming: in the process of designation one separates out objective ‘content’ from subjective ‘act’. The logical objectification (of what initially appears as subjective) proceeds through the categorization effected by the recognized parts of speech. In meaning (as opposed to mere venting) one calls upon the formal, grammatical categories of substantive, adjective or verb. These are mirrored in (or are shadows of) the logical categories of object, property and relation. While thought is not dependent upon language per se, it does depend upon some such inward articulation that respects these fixed logical categories; by contrast, the musical scale is an articulated structure, but not one which can support propositional thought.

Lotze proposed few formal innovations in logic. Among them was that found in his insistence that the coordination of part-concepts (Merkmale) in the intention of a given concept be expressed not in simple additive relations but rather in a functional representation. Instead of a simple equation, such as S=a+b+c+…, a functional notation, such as S=F(a,b,c,…), indicates that the relations of dependence among the part-concepts must be determined according to a general rule or law. (The constant reference to rules and laws furnishes a leitmotiv of Lotze’s entire philosophical endeavour.)

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Citing this article:
Sullivan, David. Logic. Lotze, Rudolph Hermann (1817–81), 1998, doi:10.4324/9780415249126-DC049-1. Routledge Encyclopedia of Philosophy, Taylor and Francis, https://www.rep.routledge.com/articles/biographical/lotze-rudolph-hermann-1817-81/v-1/sections/logic-4.
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