if often he was wrong and, at times, absurd,

     to us he is no more a person

   now but a whole climate of opinion

The entire poem is available here:

http://www.poets.org/viewmedia.php/prmMID/15543

According to Jenefer Shute, in an essay titled "Nabokov and Freud," it was not merely Freud but this "whole climate of opinion" that VN was railing against. Shute’s essay, which is available to anyone willing to dig it out from the sample pages of The Garland Companion to Nabokov at Amazon, makes a good companion to the essay by Durantaye mentioned recently by Jansy. As I read her, Shute’s main contention is that Freud is Nabokov's tar baby. The harder he tries to free himself, the more tightly the two are stuck together. Referring to the narrator of "Tyrants Destroyed," Shute writes: 

At length, it dawns on him that his mission has already been accomplished: "Rereading my chronicle, I see that, in my efforts to make him terrifying, I have only made him ridiculous, thereby destroying him--an old, proven method." (36) Nabokov evidently believes that he has engaged such a strategy against Freud--but has his endless scorn served to dominate and displace psychoanalytic discourse, or has it, on the contrary, only confirmed Freud's omnipresence? (p. 414)

VN’s attempt to laugh Freud out of existence fails, according to Shute, and she ends by saying:

Thus Nabokov's claims to a pure textuality, a discourse  somehow impervious to vulgar constraints such as "history" or "ideas," can be taken no more seriously than his claim to have banished Freud. Indeed, the very methods employed to assert the text's independence are those that undermine it; parody and polemic point insistently to the hors-texte they are designed to deny. Far from articulating an absolute freedom, they inscribe instead the horizons of a particular historical moment and the limits of authorial power. (p. 419)

My own view is that VN's attacks on Freud are, as Durentaye suggests, ill-informed and overly general in a way that VN himself otherwise deplores. What's worse, most of the attacks, many of which amount to little more than adolescent name-calling, are not up to the standard of comedy that we expect from VN. On this particular topic, he is seldom if ever funny, though he tries so hard to be. But when he tries to be serious (e.g., in characterizing Freud as promoting totalitarianism), things are even worse--he is so obviously wrongheaded that nobody with any sense could believe him. On psychobabble in general (most of which is only loosely connected to Freud), he fares better, but seldom achieves anything to match the level of satire routinely found on (say) the Cheers and Frasier TV shows. 

The history of psychoanalysis and psychotherapy contains much to be laughed at and appalled by, but VN seems not to know or care about the particulars.  And yet he rages on, and on, and on. This leads me to think that his fear and hatred of Freud was very narrowly based and that Jansy, in her message of February 6, may have hit on the crucial detail in her message of February 6: “There’s no ‘hereafter’, no transmigrating souls and no ‘metempsychosis’ to be read in Freud and his dire vision of ‘eternity.’”

What I'm suggesting is that if Freud's basic world view--a from-the-bottom-up naturalistic view--is correct, then VN's "metaphysics" is exposed as a quaint piece of wishful thinking. Only something like this, it seems to me--a threat of this magnitude--would account for the depth and irrationality of VN's rage against Freud. The fact that VN himself sometimes doubted what he so dearly, almost desperately hoped for--a life beyond this one--would only strengthen his resistance to Freud’s naturalism.

It's always possible, of course, that VN’s whole thing about Freud was just another bit of extravagant leg-pulling. In which case I suggest we all take a deep breath, relax, and sing together this little ditty by Dorothy Parker: