In this paper, I first explain Slajov Žižek’s analysis of the grounds of Kant’s categorical imperative. I show how Žižek considered the grounds of the categorical imperative to be an example of irrationalism that ran counter to the spirit of the Enlightenment, of which Kant was, ironically, a major proponent. The irrationalism in Kant’s moral law makes him vulnerable to moral skepticism. I go on to counter this interpretation by drawing from Kant’s practical philosophy. I counter the moral skeptic by arguing from moral phenomenology to the existence of a reason that is independent of empirical motivations and so objectively determining. Whatever is objectively determining logically supersedes that which is based on a particular context. The moral law is rooted in the ontology of an independent faculty of reason capable of issuing a universal law. The union of ontology and ethics means that the categorical imperative is not irrational., Daniel Paul Dal Monte, Doctoral candidate at Temple University, {"references":["Ameriks, Karl. (1982), Kant's Theory of Mind, Clarendon Press, Oxford.","Bacon, Francis. (1995), \"The New Science,\" in Isaac Kramnick (ed.), A Portable Enlightenment Reader, Penguin Books, New York, pp. 39-43.","Beck, Lewis White, (1960), \"Das Faktum Der Vernunft: Zur Rechfertigungsproblematik In Der Ethik,\" Kant-Studien, 52, pp. 271-283.","Guyer, Paul. (2007), \"Naturalistic and Transcendental Moments in Kant's Moral Philosophy,\" Inquiry, Vol. 50, no. 5, pp. 444-464.","Guyer, Paul. (1989), \"Psychology and the Transcendental Deduction,\" in Eckart Förster (ed.), Kant's Transcendental Deductions, Stanford University Press, Stanford, pp. 47-69.","Heinrich, Dieter. (1973), \"Der Begriffe der sittlichen Einsicht und Kants Lehre vom Faktum der Vernunft,\" in Kant: Zur Deutung seiner Theorie von Erkennen und Handeln, ed. G. Prauss, Kiepenhauer and Witsch, Cologne: 223-256.","Huemer, Michael. (2005), Ethical Intuitionism, Palgrave Macmillan, New York.","Kant, Immanuel. (1996), Critique of Practical Reason, translated by Mary J. Gregor, Cambridge University Press, Cambridge.","Kant, Immanuel ,(1996), Groundwork of the Metaphysics of Morals, translated by Mary J. Gregor. Cambridge University Press, Cambridge.","Kant, Immanuel ,(1998), Critique of Pure Reason, translated by Paul Guyer and Allen Wood, Cambridge University Press, Cambridge.","Korsgaard, Christine. (1996), Creating a Kingdom of Ends. Cambridge University Press, Cambridge.","Pippin, Robert. (2001), \"A Mandatory Reading of Kant's Ethics?\" The Philosophical Quarterly, vol. 51, no. 204, pp. 386-393.","Pippin, Robert ,(2000), \"Kant's Theory of Value: On Allen Wood's Kant's Ethical Thought,\" Inquiry, vol. 43, no. 2239, pp. 239-266.","Regan, Donald, (2002), \"The Value of Rational Nature,\" Ethics, 112, pp. 267-291.","Sussman, David. (2008), \"From Deduction to Deed: Kant's Grounding of the Moral Law,\" Kantian Review, Vol. 13, no. 1, pp. 52-81.","Wood, Allen. (2008), Kantian Ethics, Cambridge University Press, Cambridge.","Žižek, Slavoj. (1989), The Sublime Object of Ideology, Verso, New York."]}