Definition of: agnosticism

(ag·nos′tə·siz′əm) noun
1. The doctrine of nescience, or the theory which maintains that humans cannot have, and have not, any real or valid knowledge, but can know only impressions.
2. The theory that first truths, substance, cause, the human soul, and a First Cause, can neither be proved nor disproved, and must remain unknown or unknowable.
3. Theol. The theory that God is unknown or unknowable: distinguished from atheism.