Kornblith finds three contrasting views sitting side by side in Book III of An Essay Concerning Human Understanding (Locke). He sees this as a great strength in Locke as Locke was struggling with his reason and empiricism and certain intuitions that did not necessarily add up. With regard to natural kinds Kornblith asserts that these seeming contradictions are problems for us all; they are universal contradictions which pull us in different directions on this issue. These three views are broadly Kornblith’s own interpretation of Locke, and direct reference to their presence in the text is not made. This is a window to the larger, more contemporary discussion.
The key question: are there real kinds in nature? or do we (humans) impose them on nature for the benefit of our own understanding?
1) Conventionalist: no real kinds in nature. This is appealing as it lumps the burden of proof to the realist. Though ultimately, it seems a bit hard to swallow once you update the conversation to include evolution, chemistry, biology etc.
2) There may be real kinds in nature, but what they are is unknowable by us (locke’s official position): this seems to me to be like the worm trying to perceive the elephant. This is also a particularly British empiricist view.
3) There are real kinds in nature and what they are can be known by us. This is known as corpuscularianism. This is realism.
Two Arguments for Conventionalism:
This is an analysis of Book III, chpt vi of Locke’s Essay. It seems to be essentially a linguistic argument, pre-linguistics. Locke discusses how a word is capable of referring to kinds of things i.e. a signifier (word – cat), signified (kind – cat) and referent (an actual cat).
“The question of whether something is or is not a cat just amounts to the question of whether it does or does not answer to the idea one associates with the term ‘cat’.” (Kornblith, p18)
This seems simple enough. Locke, however, being pre-Nietzsche and pre the proper onslaught of scientific industry and culture relates these connections to metaphysical concepts:
“The measure and boundary of each Sort, or Species, whereby it is constituted that particular Sort, and distinguished from others, is that we call its Essence, which is nothing but that abstract Idea to which the Name is annexed: So that every thing contained in that Idea, is essential to that Sort.” (III, vi, 2)
Such an apparent linguistic argument seems to invoke much later philosophical thought such as that of Derrida’s differance and drift let alone any conflicts with scientific realism. This raises the interesting question of how to read linguistic or hermeneutic philosophy with regard to scientific realism. Where do they cross over, are they at odds (of course different views from different philosophers produce different contrasts). Never-the-less, this is Locke’s picture of conventionalism. One key argument he makes is a priori, the other empirical:
a priori – the essential properties of an object derive not from features of the object itself, but only from the idea associated with soem term used to pick it out. No empirical facts are called upon for this argument.
empirical – (pre-evolutionary biology, or plain modern biology) ‘irregular and monstrous births’ observed in animals give us reason to doubt whether Nature designs things by reference to a model; a regulated, established essence. Also, there are no great chasms or gaps in Nature. Rather, things differ from one another by a series of small steps. Instances might be birds that live on the ground, fishes that have wings, sea creatures that inhabit the land etc.
Essentially, modern science makes it easy to reject these sets of arguments for conventionalism. At what point does the categorization of beings stop? For instance, all animals (incl. humans) could be in the Kind named ‘built from DNA’ which would most definitely have to be an essence and therefore a negation of conventionalism.
Kornblith sees the study of these two arguments as essential. Locke himself did not fully explore the relationship of these two arguments or recognize questions that they seem to bring to the fore. Namely: our traditional taxonomy, whether there are gaps between its groupings or instead merely differences of degree – whether our taxonomy is the only possible taxonomy, or whether it is, instead, merely one among many.
As to why these questions remain important in this context, in light of scientific realism and modern advances in science and philosophy, I am not yet sure.
Chapter 3 response:
Kornblith responds to the a priori argument, being a conceptual argument, by widening the scope and introducing an empirical dimension.
“It seems to me, however, that the argument is better understood as an inference to an explanation: the idea that some properties are essential to a kind and others are not can be fully explained by way of our conceptual activity, and no other explanation seems even possible. Essential properties are thus best explained as merely a product of the way we think about the world, and there is nothing to be gained by postulating the existence of real kinds. When put in these terms, the argument does not appear to be a conceptual argument at all, and it may be defeated by offering empirical considerations which would suggest an alternative explanation of the apparent existence of essential properties of kinds.” (Kornblith, p46)
He is of course referring to advances and successes in science since the time of Locke.