Frege’s famous essay, “On Sinn and Bedeutung,” begins with the problem of identity, or equality. If a and b designate the same thing, Frege argues, then ‘it would seem that a = b could not differ from a = a.’ But the latter, as Kant argued, is an analytic statement while the former may ‘contain very valuable extensions of our knowledge’ and cannot be validated a priori. This problem sets the stage for Frege’s well-known solution: ‘a = b’ and ‘a = a’ differ in sense (Sinn) while they are identical with respect to reference (Bedeutung). More to the point, for Frege one may grasp the sense of a statement, word, thought, etc., but ‘one is not,’ he claims, ‘thereby assured of a Bedeutung.’ For Frege fiction is an example wherein one may grasp the sense of the story, follow the adventures of Odysseus for example, and yet this sense does not have a Bedeutung. As Frege puts it, ‘The thought remains the same whether “Odysseus” has a Bedeutung or not.’ In fiction, therefore, it is only the sense or thought that matters. But for Frege whatever ‘aesthetic delight’ we may derive from the thoughts associated with such fictional accounts, the will to truth (to borrow a phrase from Nietzsche) will lead us to move beyond them: ‘The question of truth would cause us to abandon aesthetic delight for an attitude of scientific investigation.’ Or again: ‘It is the striving for truth that drives us always to advance from the sense to the Bedeutung.’ It is this striving for truth, this will to truth, that drove Heinrich Schliemann on his quest to determine whether story of the Iliad were merely a story or whether Troy actually existed – that is, he sought to determine whether or not the Sinn of ‘Troy’ had a Bedeutung.
This argument leads Frege to a very specific sense of what it means to conceive things. On the one hand, we can have many thoughts – fiction is full of thoughts – but the will to truth pushes Frege to an account of propositions (or assertoric sentences) where the thought is taken to be the sense of the proposition and the truth-value is its Bedeutung. In the context of these arguments Frege develops an important theory of concepts, and in effect replaces the subject-predicate distinction with the concept-object distinction, with concepts taking on the predicative function, but in a much broader fashion than was traditionally done by predicates. Put briefly, a concept is an unsaturated function that is related to the object(s) that would fulfill and saturate the function. As Frege puts it, ‘if we complete the name of a concept with a proper name, we obtain a sentence [proposition] whose sense is a thought; and this sentence [proposition] has a truth-value as its Bedeutung.’ Moreover, for Frege there is nor room for vague concepts, or anexact concepts (and on this point Husserl takes a quite different path). For Frege ‘It must be determinate for every object whether it falls under a concept or not; a concept word which does not meet this requirement on its Bedeutung is bedeutunglos.’
I began with Frege in order to get to Spinoza, and especially to a common attempt among Spinoza commentators to read his propositions as logical propositions, or as modal statements that make claims regarding necessary truth. As Richard Mason argues in his book on Spinoza, The God of Spinoza, Edwin Curley is quite right when he claims that ‘One thing every interpreter of Spinoza agrees on is that Spinoza connects causal relation with the relation of logical consequence’; but once this move is made, Mason correctly notes, then Spinoza’s thought is open to the Humean criticism that follows upon his arguments that causal relations are not logical relations. But are we justified in following Curley when he claims that despite Spinoza’s talk of the existence of things rather than what can be correctly said of things that this ‘need not prevent us,’ he argues, ‘from translating what he says about things into talk about truths and developing a general account of necessary truth that will accord with Spinoza’s intentions.’ This ties in with the arguments Mason makes in his book, Before Logic (which I discuss here), that between Spinoza and Leibniz there is a choice: Spinoza prefers to talk about things without worrying whether such talk can be translated into a modal logic of necessary truth, and Leibniz attempts to translate talk about things into talk about truths and the modal logic that comes with this.
All this has important consequences for understanding Spinoza, but right off the bat we can see why Nietzsche would have seen in Spinoza an important precursor (which I discuss in my Philosophy at the Edge of Chaos) in that the will to truth was not something that infected Spinoza’s thought. We can also see that by not reading Spinoza as a failed or at least poorly equipped modal logician (as Jonathan Bennett reads Spinoza) we are able to rehabilitate Spinoza against these criticism and in the process show that Spinoza is more closely aligned with Hume the empiricist than Leibniz the rationalist, which is where historians of philosophy since Kant have largely categorized Spinoza. And finally, the discussions here point to an important aspect of Deleuze’s thought, though one that is often overlooked by Deleuze scholars, and that is Deleuze’s insistence that while philosophy is concerned with concepts, and with creating concepts, it is not primarily in order to engender propositions that will register a truth-value and hence become incorporated into a logical and scientific view of the world; rather, the task of philosophy will be to create concepts that facilitate thoughts that are relevant rather than true, and which may indeed be taken up by science. For philosophy, then, the task is the relevance of problems and concepts, and this is indeed true for science as well, but in the case of science such problems and concepts are subservient to the true propositions that are the standard whereby the success of science is measured. A philosophy’s success is not measured by truth, but by the relevance of its concepts such that one can draw upon Platonic, Aristotelian, Spinozist, or Humean concepts in a way that elucidates the contemporary slate of different and ever-changing problems.