Abstract: Dessauer holds different views of thing-in-itself from Kant and Engels， but there is a paradox in his ideas. Kant unknowable thing-in-itself contains the perceptual one and the ideal one， which have different relationships with empirical objects. Dessauer regards the thing-in-itself of nature objects (TII₁) as Kants perceptual one and the thing-in-itself of artifacts (TII₂) as Kants ideal one， thus separating TII₁ and TII₂ completely. TII₂ hides itself in the technological ideas created by God， which can be materialized with human beingstechnological invention activities. Compared to scientific understanding activities， human beings broaden and experience the possible territories created by God with their technological invention activities. TII₂ is known while TII₁ is unknown. Based on the empirical facts， human beings construct TII₂ based on TII₁， and TII₂ contains human beingspurposes or intentions， which is of identity with TII₁ to some extent.

Key words: Immanuel Kant, Friedrich Dessauer, thing-in-itself, artifact, paradox