Immanuel Kant in his Lectures on Philosophical Theology  treats the Cosmological Argument as if it functions as resting on a presupposition: i.e., that something exists, and I am having an experience of that existence. Thus, this simplest experience is expressed by Kant:
It is just the experience that I am [ … ] I argue as follows: I am either necessary or contingent. But the changes which go on in me show that I am not necessary. Therefore I am contingent. But if I am contingent, there must be somewhere external to me a ground for my existence, which is the reason why I am as I am and not otherwise. This ground of my existence must be absolutely necessary [ … ] This is absolutely necessary being, however, must contain in itself the ground of its own existence, and consequently the ground of the existence of the whole world. 
However, Kant faults this argument along with the Ontological Argument – or what he considers the “Transcendental Proof” – because the primary source of the Cosmological Argument hinges off an empirical one (i.e., that something exists and I experience it), but beyond that we have to deal with “pure concepts.” Therefore, Kant suggests that in “the cosmological proof the transcendental proof is presupposed as correct and gives the cosmological proof all its strength” .
Even moreover, if the transcendental proof were invalid, then as too would the cosmological proof along with it. It is of an interesting note that Kant first regarded Leibniz’s cosmological argument (a contingentia mundi) as an a posteriori proof, but then later regarded it as an a priori like the ontological proof. Thus, Kant further critiques, “The precise concept of God is the concept of a most perfect thing. But I can never derive such a concept from experience, for the highest perfection can never be given me in any possible experience.” 
More so that Kant would be unable to conclude that “only one being has produced” the “magnitude, order, and chainlike combination of all things in the world.” Allen Wood  thinks that Kant gathered this point from David Hume, where he once wrote in his Dialogues Concerning Natural Religion:
And what shadow of an argument, continued Philo, can you produce, from your hypothesis, to prove the unity of the Deity? A great number of men join in building a house or ship, in rearing a city, in framing a commonwealth: why may not several deities combine contriving and framing a world? This is only so much greater similarly to human affairs. .
However, Kant is sympathetic to say that he couldnt refute this supposition from his mere experience of the world. Thus, to finish on his point: “The abstraction of concepts of God from these empirically founded perceptions can beget nothing but contradictory systems. Our experience of the world is too limited to permit us to infer a highest reality from it. Before we could argue that the present world is the most perfect of all possible ones and prove from this that its author is of the highest perfection, we would first have to know the whole totality of the world, every means and end reached by it. The natural theologians have certainly never reached it” .
-  Immanuel Kant, Lectures on Philosophical Theology, trans. by Allen W. Wood and Gertrude M. Clark (Cornell University Press: 1978)
-  Ibid., p. 35
-  Ibid.
-  Ibid., p. 37
-  Ibid., p. 37 (see note 6)
-  David Hume, Dialogues Concerning Natural Religion, Part V (New York: 1948) p. 39
-  Kant, 38