The opening chapter of Meillassoux’s After Finitude begins with a discussion pertaining to the classic distinction between primary and secondary qualities in metaphysics. According to Meillassoux, the shift that occurred in what is commonly called modern philosophy was an alteration in precisely this distinction.
Pre-critical metaphysics was resolutely realist in its conception of the distinction between primary and secondary qualities: from Plato to Leibniz, primary qualities inhered within the things themselves (the thing-in-itself), while secondary qualities required some form of givenness (whether conscious or otherwise) to obtain. Meillassoux uses the example of the sensation of burning oneself on a candle to illustrate the difference: “When I burn myself on a candle, I spontaneously take the sensation of burning to be in my finger, not in the candle. I do not touch a pain that would be present in the flame like one of its properties: the brazier does not burn itself when it burns.” So, secondary qualities clearly need a subject to actualize them. Colors are seen, and do not exist as colors without an intentional subject. Pain is felt, and cannot be felt without this same subject. But what about properties like size, weight, and shape? Classically conceived, these properties inhered within things themselves, and required no subject in order to obtain. So goes pre-critical metaphysics.
Meillassoux gives the name ‘correlationism’ to the critical turn in modern philosophy that rejects this thesis of the distinction between primary and secondary qualities. According to the modern philosopher, this “is an indefensible thesis because thought cannot get outside itself in order to compare the world as it is ‘in itself’ to the world as it is ‘for us’, and thereby distinguish what is a function of our relation to the world from what belongs to the world alone. Such an enterprise is effectively self-contradictory, for at the very moment when we think of a property as belonging to the world in itself, it is precisely the latter that we are thinking, and consequently this property is revealed to be essentially tied to our thinking about the world. We cannot represent the ‘in itself’ without it becoming ‘for us’, or as Hegel amusingly put it, we cannot ‘creep up on’ the object ‘from behind’ so as to find out what it is in itself – which means that we cannot know anything that would be beyond our relation to the world.” Thus, we understand the correlate here referred to as the correlation between thought and being – and its place in modern philosophy as the trump card against naïve metaphysical dogmatism (i.e. the knowability of the in-itself).
Therefore, the difference between objective representation (statements of fact) and subjective representation (statements of value or feeling) becomes simply two different forms of subjectivity: those that can be universalized and those that cannot. Consequently, science becomes concerned with intersubjectivity, as opposed to adequation, as correspondence to primary qualities as the mode of truth is supplanted by communitarian consensus. As a result, according to Meillassoux, “one could say that up until Kant, one of the principle problems of philosophy was to think substance, while ever since Kant, it has consisted in trying to think the correlation.”
This move towards the primacy of the thought-being correlation was made by Kant in order to stave off what he called dogmatism – the attempt to ground reason in the thing-itself, as opposed to his own method of transcendental reduction, made in the Critique of Pure Reason, which effectively moved the absolutes of pre-critical metaphysics (time and space) from the object to the transcendental subject. Time and space are not (necessarily) properties of things-in-themselves, but categories of the mind meant to shape phenomena into sensible impressions.
Meillassoux’s argument against correlationism is not one of questioning its historical worth – without a doubt, Kant’s ability to assuage Hume’s skepticism while staving off metaphysical dogmatism is truly revolutionary – but of its internal consistency. Meillassoux’s question is this: If the thought-being correlation is to be considered primary in philosophy, then how can one think of a time when one of these two was not? “How are we to grasp the meaning of scientific statements bearing explicitly upon a manifestation of the world that is posited as anterior to the emergence of thought and even of life – posited, that is, as anterior to every form of human relation to the world?” Meillassoux calls ancestral any thing or event that is dated to have preceded the emergence of thought, and arche-fossil any contemporary thing that traces back to an event anterior to terrestrial life.
Meillassoux’s claim is that any and all forms of correlationism are unable to consistently accept the findings of modern science as regards ancestral events (such as Big Bang cosmology, evolutionary theory, and radioactive decay) while simultaneously holding to the primacy of the thought-being correlation. For example, as regards the dating of the accretion of the earth, the scientist will adopt an instinctively realism: “the accretion of the earth preceded the advent of humans by x number of years”. On the other hand, the correlationist must resort to the critical gesture: “The present community of scientists has objective reasons to consider that the accretion of the earth preceded the emergence of hominids by x number of years.” This scientific statement trades on universal intersubjectivity, and not adequation, making it useless for anything save the social sciences. It then becomes clear why “scientists are much more likely to side with Cartesianism than with Kantianism…”
Correlationism’s attitude towards the ancestral is summed up well in Husserl’s words: ““The existence of nature cannot be the condition for the existence of consciousness since Nature itself turns out to be a correlate of consciousness: Nature is only in being constituted in regular concatenations of consciousness.” In other words, it is impossible for any form of correlationism to think the possibility of the emergence of one of the terms of its primary correlate. In this way, the correlate takes the place of the pre-critical God – that which subsists in-itself and is casua sui. To think of the coming-into-being of thought should be as much heresy for the correlationist as thinking the coming-into-being of God is for orthodox theology. That which ultimately guarantees meaning (or even the lack thereof) cannot be said to have at some time been not.
In this way, Meillassoux likens this correlationist circle (where the thought-being correlation must originally be thought) to the reactionary attitude towards science exhibited by biblical creationists who, when confronted with evidence of an old earth, “reply unperturbed that God also created at the same time as the earth 6,000 years ago those radioactive compounds that seem to indicate that the earth is much older than it is – in order to test the physicist’s faith. Similarly, might not the meaning of the arche-fossil be to test the philosopher’s faith in correlation, even when confronted with the data which seem to point to an abyssal divide between what exists and what appears?”
For Meillassoux, the reality of the ancestral realm poses this challenge to modern philosophy: how to conceive of a time in which the given as such passes from non-being into being. If, as Kant held, the absolutes (space and time) are not properties of the things themselves, but categories of the mind, then how can science “think a world wherein spatio-temporal givenness itself came into being within a time and a space which preceded every variety of givenness?” Thus, we have the problem of the ancestral: the arche-fossil invites us to get outside of our minds and to grasp the in-itself, but the critical conscience warns us of imminent dogmatism if we accept.
 Quentin Meillassoux, After Finitude (London: Continuum, 2008), 1.
 Ibid., 3-4.
 Ibid., 4-5.
 Ibid., 6.
 Ibid., 10.
 Ibid., 15.
 Ibid., 13.
 Edmund Husserl, Ideas Pertaining to a Pure Phenomenology and to a Phenomenological Philosophy: First Book: General Introduction to a Pure Phenomenology (Berlin: Springer, 1983), 116.
 Meillassoux, After Finitude, 18.
 Ibid., 21.
 Ibid., 22.