Probably not. Recently we found a counter example to Lovelock theorem, and proved that Einstein's general relativity is not unique. The theory we found is general covariant, propagates only the massless graviton, and is free from ghost instabilities. It respects all criteria of Lovelock's theorem, but nevertheless exhibits modified dynamics, including the singularity resolution for spherically symmetric solutions, the modified dispersion relation of gravitational waves, and others. Our discovery challenges the distinctive role of general relativity as the unique non-linear theory describing gravitational interactions in the four dimensional space-time.