It comes from Voline's The Unknown Revolution:

The paradox of Makhno's character was that, despite his superior power of will and character, he was never strong enough to resist certain temptations, and with him he dragged down several of his friends and collaborators. Sometimes, however, it was the latter who dragged him down, and he was unable to oppose them resolutely.

His greatest fault was certainly the abuse of alcohol. He became addicted gradually, but at certain periods his condition was disgraceful in its manifestations. The effects of his drunkenness were primarily in the moral field. Physically he did not change, but under the influence of alcohol he became over-excited, mischievous, unjust, intractable and violent. Often, during my stay with the army, I left him in despair, unable to get anything reasonable out of him even when matters of some importance were concerned, because of his abnormal condition. (At certain periods, indeed, it became almost his "normal" condition!)

The second fault of Makhno and of many of his intimates — both commanders and others -— was their behaviour towards women. Especially when drunk, these men let themselves indulge in shameful and even odious activities, going as far as orgies in which certain women were forced to participate. It goes without saying that these acts of debauchery produced a demoralising effect on those who knew about them, and Makhno's good name suffered from this.