Topics Worth Investigating

  1. Relate Kant's argument that "existence is not a predicate" to the problem of existential import in syllogistic logic. Are we faced with two radically different logics?

  2. Søren Kierkegaard writes

    If it were proposed to prove Napoleon's existence from Napoleon's deeds, would it not be a most curious proceeding? His existence does indeed explain his deeds, but the deeds do not prove his existence, unless I have already understood the word "his" so as thereby to have assumed his existence. But Napoleon is only an individual, and insofar there exists no absolute relationship between him and his deeds; some other person might have performed the same deeds. Perhaps this is the reason why I cannot pass from the deeds to existence. If I call these deeds the deeds of Napoleon, the proof becomes superfluous, since I have already named him; if I ignore this, I can never prove the deeds that they are Napoleon's, but only in a purely ideal manner that such deeds are the deeds of a great general, and so forth.[1]

    Evaluate Kierkegaard's argument by setting up a syllogism to the conclusion, "Napoleon is an existent being" from the premises Kierkegaard mentions. Why must "existence" be presupposed in the argument?

  3. Aristotle argues in his "The Sea-Fight Tomorrow," a selection in this book, as follows:

    For it is manifest that the circumstances are not influenced by the fact of an affirmation or denial on the part of anyone. For events will not take place or fail to take place because it was stated that they would or would not take place, nor is this any more the case if the prediction dates back ten thousand years or any other space of time. Wherefore, if through all time the nature of things was so constituted that a prediction about an event was true, then through all time it was necessary that that should find fulfillment; and with regard to all events, circumstances have always been such that their occurrence is a matter of necessity.[2]

    Is the problem concerning "future truths" related to the problem of existential import? Try to relate the problem of existential import to the notions of possibility and actuality.

  4. William C. Kneale, a well known historian of logic, writes:

    Too often philosophers merely remark that Kant refuted the argument by showing that existence is not a predicate and that "one cannot build bridges from the conceptual realm to the real world." But it is very doubtful that Kant specified a sense of "is a predicate" such that, in that sense, it is clear both that existence is not a predicate and that Anselm's argument requires that it be one. Nor are the mere claims that no existential propositions are necessary or the above comment about bridge building impressive as refutations of Anselm—after all, he claims to have an argument for the necessity of at least one existential proposition. So one must either show just where his argument goes wrong, or else produce a solid argument for the claim that no existential (in the appropriate sense) propositions can be necessary—and this, I think, no one has succeeded in doing.[3]

    If I state, "Pegasus exists," aren't I making a false claim that Pegasus is an existent thing? In what sense could existence in the statement be a predicate?



Søren Kierkegaard. Philosophical Fragments. Trans. David F. Swenson. Princeton: Princeton University Press, 1967, 32-33.


Aristotle. On Interpretation, 8:35-9:4.


William Calvert Kneale. "Is Existence a Predicate?" in Proceedings of the Aristotelian Society, Supplementary Vol. 15. Reprinted in Readings in Philosophical Analysis. Ed. Herbert Feigl and Wilfrid Sellars. New York: Appleton-Century-Crofts, Inc., 1949, 29.