“Meaningless! Meaningless!” says the Teacher. “Utterly meaningless! Everything is meaningless.” (Ecclesiastes 1:2)
In Part 1 of Notes from Underground, Dostoyevsky’s Underground Man claims that consciousness is a disease. In a loose sense, given certain assumptions, Underground Man makes a significant point. In a strict sense, however, he is wrong. Let me explain.
First, we need some background. Dostoyevsky was a 19th Century Russian novelist and philosopher. He is widely recognized as one of history’s greatest novelists. He was also a Christian. Dostoyevsky wrote Notes from Underground as a critique of philosophical naturalism. This worldview was popular among Western intellectuals in the late 19th Century and continues to be an influential position. Dostoyevsky’s main character, an unreliable narrator called “the Underground Man,” is a disillusioned intellectual who sees the implications of naturalism and rebels against life in such a world. Early in the novella, Underground Man makes his claim: consciousness is a disease. Is he right?
Let us articulate a working definition of consciousness; for without such a definition, it will be difficult to speak intelligently about Underground Man’s assertion. It is hard to provide a non-circular, essential definition of consciousness. As such, I agree with J. P. Moreland that consciousness is best defined ostensively, i.e., by pointing to specific examples such as sensations, thoughts, beliefs, desires, and volitions.  So, if consciousness is a disease, then the human ability to think, believe, and choose is an illness. In which sense is it an illness?
Since Dostoyevsky was a Christian, let us approach the question from a view on the meaning of human life called Purpose Theory (PT). On this view, God’s existence and telic creation of human beings are necessary conditions for human life to be objectively meaningful. Thus, if human life is objectively meaningful, then God exists and created us for a good purpose. But if there is no God, and consequently no divine design of human beings, then human life is objectively meaningless. Now, on the conjunction of PT and naturalism, it follows that human life is objectively meaningless. Sic vita est. Underground Man recognizes that nihilism follows from the naturalism of his culture and he rails against the idea of human existence in a meaningless world. Underground Man’s discontent frames the context for his claim that consciousness is a disease.
In a world of nihilistic naturalism, consciousness can be quite unpleasant. In such a world, man might be defined as the animal which is capable of awareness that it is an objectively meaningless conglomeration of atoms moving randomly in a universe bereft of purpose and value and destined to annihilation by heat death. Unpleasant indeed. It is in this sense that Underground Man considers consciousness a disease. As the Teacher noted in Ecclesiastes 1:18, in a world “under the sun” (i.e., as I take it, a naturalistic world), “the more knowledge, the more grief.”
However, in the strict sense of “disease,” Underground Man is imprecise to call consciousness a disease. Assuming the conjunction of PT and naturalism, there is no objective way things ought to be. Without such a standard, the term “disease” loses meaning; for something’s being diseased presupposes a standard of wellness, an objectively valuable way according to which that thing ought to function. As such, Underground Man would be more precise if he were to say that consciousness is a vexatious and fleeting accident. (In Chapter IX of Part 1, Underground Man is somewhat more exact, describing consciousness as a “misfortune.” This vocabulary is apt, since fortune is synonymous with chance. On naturalism, chance rules. Yet “disease” has a certain poetic appeal, especially coming from Dostoyevsky’s splenetic anti-hero.)
There is another problem. On naturalism, it is difficult to account for the existence of consciousness. Again, I agree with Moreland, this time writing on pg. 74 of The Soul: naturalism does not explain consciousness. Hence, plausibly, Underground Man is mistaken in calling consciousness a disease in a naturalistic world. In such a world, it seems likely that there would be no consciousness at all, and thus no mistaken references to consciousness. In fact, there would be no reference whatsoever!
But it is obvious that there is consciousness. We use language to refer to extralinguistic, non-mental objects. Our minds have the power of intentionality. We think, form beliefs, and make choices. These facts give us reasons to reject philosophical naturalism. Moreover, if human life is objectively meaningful, then a significant triad of propositions follows: (1) philosophical naturalism is false; (2) God exists; and (3) God created human beings for a good purpose. Underground Man helps us to see this triad, even though his terms are somewhat vague and his attitude is, shall we say, a bit grouchy.
“Now all has been heard; here is the conclusion of the matter: Fear God and keep his commandments, for this is the duty of all mankind.” (Ecclesiastes 12:13)
 See pg. 5 in Notes from Underground (New York: Bantam Dell, 2005). On pg. 4, Underground Man claims that excessive consciousness is a disease. But on pg. 5, he claims that consciousness as such is a disease.
 Roughly, philosophical naturalism is the view that reality is nothing but physical. Hence, no non-physical or immaterial things exist. This view is sometimes called philosophical materialism.
 In A Confession, Tolstoy addresses the same worldview, indicating that he believed it entails the objective meaninglessness of human life. Referring to naturalism, Tolstoy wrote: “but in this sphere of knowledge the only answer to my question, “What is the meaning of my life?” was: “You are what you call your ‘life’; you are a transitory, casual cohesion of particles. The mutual interactions and changes of these particles produce in you what you call your “life”. That cohesion will last some time; afterwards the interaction of these particles will cease and what you call “life” will cease, and so will all your questions. You are an accidentally united little lump of something. That little lump ferments. The little lump calls that fermenting its ‘life’. The lump will disintegrate and there will be an end of the fermenting and of all the questions.” See https://en.wikisource.org/wiki/A_Confession_(Maudes_translation)/VI
 See J. P. Moreland, The Soul: How We Know It’s Real And Why It Matters, (Chicago: Moody Publishers, 2014), pgs. 77-78. On pg. 77, Moreland provides a characterization of consciousness as “what you are aware of when you engage in first-person introspection.” This is an adequate characterization. Arguably, however, if taken as an essential definition of consciousness, the characterization is circular. ‘Aware’ is a synonym of ‘conscious.’ So, to say that consciousness is what you are aware of when you engage in first-person introspection is to say that consciousness is what you are conscious of when you engage in first-person introspection. This will not do as a formal definition, since consciousness is defined in terms of being conscious.
 For more information on PT, see Thaddeus Metz, “Could God’s Purpose be the Source of Life’s Meaning?” in Exploring the Meaning of Life: An Anthology and Guide, edited by Joshua W. Seachris, (Wiley-Blackwell, 2013). See also Elliott R. Crozat, Does the Purpose Theory of the Meaning of Life Entail an Irrational God? in Philosophia Christi, Vol. 20, No. 2, 2018.
 By “objective,” I mean that which exists independently of human thought, belief, or desire. Therefore, if human life is objectively meaningful, then human life has meaning regardless of our thoughts, beliefs, and desires.