There were some important philosophical differences. Gnostics emphasized magic and ritual in a way that would have been disagreeable to the more sober neoplatonists such as Plotinus and Porphyry, though perhaps not to later neoplatonists such as Iamblichus. Gnostics were in conflict with the idea expressed by Plotinus that the approach to the infinite force, which is the One or Monad, cannot be through knowing or not knowing. Although there has been dispute as to which gnostics Plotinus was referring to, it appears they were Sethian.