Freud wasn't selfish when it came to cutting human flesh. Thus, in his letter of July 17, 1873, aged only 17, the young Freud, invited his friend, Eduard, to participate in the cutting of a corpse writing,
You can easily catch up with me and make your first cut on a human cadaver in my company. (1)
This is a very generous offer, but where would Freud gain access to a corpse, having just finished his high school studies on July 9, 1973, thus only a week earlier, during the summer vacation?
Keeping in mind that Freud's daughter Anna was the one who transcribed the letters, let's have a look at the whole quote.
So, if you decide to become a physician, you can easily catch up with me and make your first cut on a human cadaver in my company; if you opt for diplomacy, of course, no one will ever catch up with you, not even history. To this end, I shall be attending the philosophy faculty during my first year. (1)
Without a shred of doubt, the quote had been severely tampered with, which is easy to prove. And, the fact, that it needed to be tampered with, indicates that the quote is far from innocent.

Remarkably, the quote contains a conditional close: if you decide to become a physician, but - as Freud was well aware of - Siberstein had no such plans. And the claim that he would opt for diplomacy is even more absurd. Eduard wasn't even contemplating either option. As Freud revealed in several of his letters to Eduard - for the first time, on September 18, 1874 - Eduard's choice was legal studies (2) in Leipzig. (In the letter to his fiancé, ten years later, on February 7, 1884, Freud informed her: 

my friend Silberstein, ... has become a banker, because he didn’t like jurisprudence.) (3)
Also, the statement, no one will ever catch up with you, not even history, makes no sense at all. History doesn't catch people, the police do.

No one will ever catch you

Let's see what this statement would have looked like without the misleading additions to its content. How about:
you can easily catch up with me and make your first cut on a human cadaver in my company; no one will ever catch you.
And, as if it was somehow beneficial for his cadaver cutting, Freud added:  
To this end, I shall be attending the philosophy faculty during my first year.
It is apparent, in this cadaver-cutting context, that the reference to Freud's philosophy studies makes no sense. How could Freud get access to a cadaver while studying philosophy?
As always, the chronology is important. It was first during, the fall of 1873 that he [Freud] registered at the University of Vienna. (4)
`And the cadaver-cutting offer was made, almost two months earlier, in his letter to Eduard of July 17, 1873!

In the letter, to Eduard, of January 22, 1874, thus, only seven months later, written, allegedly, in a dissection hall, Freud explained, apparently including his friend, that, "We cannot” in the presence of the corpse. *
The same question as previously applies to this letter. If Freud was devoting his studies to only purely humanistic studies, what was he doing in the dissection hall not, as yet, studying medicine?
The message is odd, not only because it is so brief, but because it doesn't make much sense. Was Freud regretting not being able to have sex with his boyfriend, Eduard, in the presence of the corpse? Or, maybe, he was rather regretting being unable to have sex with the corpse in Eduard's company? (Since Freud's daughter, Anna, bowdlerised Silberstein letters, anything is possible.)

Intercourse with dead bodies

Notably, in the autobiographical work, Three Essays on the Theory of Sexuality of 1905, Freud informed the world that, in cases of licking excrement or of intercourse with dead bodies ... we should not be too ready to assume that people who act in this way will necessarily turn out to be insane or subject to grave abnormalities of other kinds. **
And since the Freudian pseudo-science of psychoanalysis was based on his deranged mentality, this statement appears to paint a perfect Freudian self-portrait.
What specifically points in Freud's direction is the fact that rather than talking about, a much more common, coprophilia, thus eating of faeces, in which he engaged, he was recounting, a more unusual, licking [of] excrement.
This kind of subterfuge, often used by him, to avoid revealing his perverted preferences, always points in one direction only, thus to Freud.
* Freud, Sigmund, The Letters of Sigmund Freud to Eduard Silberstein, 1871-1881, (1989, p. 24).
** SE 7, p. 161.

Having acquired a scholarship to a research station in the Italian town of Trieste, Freud didn't waste time sitting at home. This is how, on his arrival, Freud described the women of Trieste, in his letter to Eduard on March 28, 1876:
Trieste is a very beautiful city and ... the beasts are very beautiful beasts. *
This succinct statement reveals the young Freud's - aged 20, at the time -  attitude toward women. For him, women are beasts and, thus, not really human beings.
How do we know that the beasts Freud referred to were women? This is apparent from his letter of  April 23, 1876, p. 153, in which, having visited the town of Muccia, Freud wrote, that even the [local] women were pleasing to behold, whereas the corresponding class of population in Trieste, which ought by rights to be beautiful, is brutta, brutta [ugly]. True, on my first day in Trieste, I felt that the city was inhabited by none but Italian goddesses. **
So, we have it confirmed that the beasts of Trieste were women.

Bella Italia

This is significant because, on April 5, 1876, Freud told Eduard:  I would much rather report to you on what I have been able to see of bella Italia, and how I serve the beast-killing (Zooktonos) science. **
The addition of the Greek word that means animal killing could refer to Freud's duty at the marine laboratory where he was employed. On the other hand, the fact that the Greek word had to be added, most probably not by Freud, who could as well have written it in German, is suspicious.
This is the only time that a Greek term appeared in any of Freud's letters to Silberstein. So what was the beast killing science?
Was it about killing the fauna of the ocean, or about killing ugly women?
* Freud, Sigmund, The Letters of Sigmund Freud to Eduard Silberstein, 1871-1881, (1989, p. 141).
* Freud, (1989, p. 153).
** Freud, (1989, p. 142).

As he recounts on April 5, 1876, he enjoyed sightseeing, in particular, not uncommon for a paedophile, showing a keen interest in young children. Few small children appear on the streets, he wrote. Those I have seen look very precocious, and already temper their beauty with face powder. *
Rather than continuing his walk around town, Freud contemplated a vivisection of the children in the street. Regretting that he immediately could not use his scalpel on the children, Freud wrote, Since it is not allowed to dissect human beings, I really have nothing to do with them. *
Wasn't it unlucky for the young Freud that dissecting humans was not allowed? Notably, Freud skips one stage in his expose.
Unless he intended to dissect them alive, he would have to kill them first. And, whether he had nothing to do with them is doubtful.
Maybe, after all, he allowed himself to make a cut of one or more Italian cadavers.
Freud's interest in children is apparent from his letter to Eduard of April 23, 1876, in which having visited the town of Muccia, Freud informed his friend that, the local children, were assai belle [pretty enough], half of them rustic beauties. **
On this occasion, Freud's refrained, at least in his letter, from contemplating dissecting children.
* Freud, Sigmund, The Letters of Sigmund Freud to Eduard Silberstein, 1871-1881, (1989, p. 146).
** Freud, (1989, p. 153).