This quote from Leonardo da Vinci underscores his belief in the integration of intellectual and practical skills in the creation of art. Da Vinci himself was a quintessential example of this philosophy, being both an artist and an inventor whose studies in anatomy, science, and engineering deeply influenced his artistic work.

Here's a breakdown of what this quote might mean:

Spirit: Often interpreted as creativity, inspiration, or the conceptual aspect of art. This represents the idea, the vision, or the passion behind the artwork.

Hand: Symbolizes the physical execution, the skill of craftsmanship, and the technical ability to translate ideas into tangible forms.

No Art: Without the synergy between these two elements, art, in its truest form, cannot exist. It suggests that art is not just about having an idea but also about the capability to materialize that idea with skill and precision.

Da Vinci's work, like "The Last Supper" or "Mona Lisa," reflects this philosophy where scientific observation and artistic expression are intertwined. His notebooks further illustrate this, filled with both sketches of human anatomy and designs for inventions, showing how one informed the other.

This quote encourages artists to not only be dreamers but also doers, emphasizing that true art requires both innovation in thought and excellence in execution. It's a call to harmonize the mind's creativity with the hand's capability, which is particularly relevant in an age where digital and traditional arts blend more than ever.