“A Conversation with Leonardo” presents a complex debate between past and present, idealism and realism, faith and skepticism, art and nature. The dialogue, however, ultimately revolves around one central theme: the observation Protagoras made more than two thousand years ago that “Man is the measure of all things.” Leonardo is the heir and representative of a venerable tradition, which first defines man in absolute, nonhuman terms, and then measures man against that model. Either as the container of its feeble spark, the pinnacle of its creation, or at the very least, its imperfect image, for the traditional humanist, humankind’s significance depends upon some alleged connection with divinity.
Against this religious version of humanism, Ciardi places another, more modern form, which developed out of René Descartes’s assertion, “I think, therefore I am.” When the narrator tells Leonardo, “I’m/ thinking you,” he is clearly echoing the revolutionary words that place humanity at the center of humanity’s understanding and significance. No longer the shadow, idea, or handiwork of something intangible and incomprehensible (“the abstraction of nothing”), this vision secularizes man, making of him the first and only measure of himself, of what he actually is.
As Miller Williams writes in The Achievement of John Ciardi (1969), this kind of secular humanism is only attained when one gives “his whole attention to the moment he is living.[This is] the affirmation of the eternal present.” Such an affirmation, however, often requires a high price, as the title of another Ciardi poem, “Nothing is Really Hard But to Be Real,” suggests. The stubborn attachment to the here and now, to scientific proof and sober reason, prevent the towering visions that stir and lift the heart: Renaissance men such as Leonardo have little place in a humanism of human proportions, except perhaps in its dreams and memories. Closing with an air of melancholy, the poem hints that both sides inevitably suffer loss and disillusionment, notwithstanding their respect for and commitment to the same central belief in humanism. The narrator’s awakening in the final stanza is not only literal, but metaphorical as well, for only by disillusioning Leonardo does he see clearly the extent of his own disillusionment. For him, it is now “pointless to try for sleep again in nature”; he has woken and faces his own solitude in a diminished world unilluminated by faith in God, man, or ideals.