Lying is knowing the truth while intentionally deceiving. Bullshitting is deceptive as well, yet is not so deliberately against truth. Bullshit casually bypasses truth altogether to achieve an effect.
Lying, perversely, subverts the truth: you must know the truth to lie. Bullshitters don’t care. Bullshit only concerns itself with achievement, making it more dangerous as it erodes the social foundation of truth-seeking and trust bias.
from Harry Frankfurt, “On Bullshit”