“For the things that are seen are temporal, but things that are unseen are eternal.”

Variant: We look not at the things which are what you would call seen, but at the things which are not seen. For the things which are seen are temporal. But the things which are not seen are eternal.
Source: A Wrinkle in Time

As quoted in The Anchor Book of Latin Quotations: with English translations‎ (1990) by Norbert Guterman, p. 375
Disputed

Works, VII, 17.
Context: The great thing however is, in the show of the temporal and the transient to recognize the substance which is immanent and the eternal which is present. For the work of Reason (which is synonymous with the Idea) when considered in its own actuality, is to simultaneously enter external existence and emerge with an infinite wealth of forms, phenomena and phases — a multiplicity that envelops its essential rational kernel with a motley outer rind with which our ordinary consciousness is earliest at home. It is this rind that the Concept must penetrate before Reason can find its own inward pulse and feel it still beating even in the outward phases. But this infinite variety of circumstances which is formed in this element of externality by the light of the rational essence shining in it — all this infinite material, with its regulatory laws — is not the object of philosophy.... To comprehend what is, is the task of philosophy: and what is is Reason.

My Exit, Unfair.
Catch For Us The Foxes (2004)

1930s, Die verfluchten Hakenkreuzler. Etwas zum Nachdenken (1932)

Source: Purification of the Heart: Signs, Symptoms and Cures of the Spiritual Diseases of the Heart

Sic et Non (1120)

Sic et Non (1120)