In Chapter 8, Henry Jekyll referred to his document which constitutes the entirety of Chapter 10 as "the confession of your unworthy and unhappy friend--Henry Jekyll," yet this final Chapter refers to the
document as a "full statement." This statement, then, gives us an account of Dr. Jekyll's experiments and along with the preceding Chapter, it constitutes what the average person considers as the entire Jekyll/Hyde story.
In giving us his background, Jekyll constantly emphasizes the excellence of his background which commands the respect of all; his honorable conduct is exemplary to the world, when contrasted with the "blazon irregularities" which he hid with a morbid sense of shame. Thus, early in Jekyll's life, he recognized a "profound duplicity of life so profound a double dealer." He also recognized early "that man is not truly one, but truly two," and then he acknowledged "the thorough and primitive duality of man." Also, very early, he saw the need to hide the shameful part of himself from the world, and the necessity to try and separate the two selves.
Note here that many critics are not content to interpret the novel as a conflict between good (Jekyll) and evil (Hyde), but, instead, the novel points out, according to them, that evil (represented by Hyde) is only a small portion of man, a portion represented by Hyde's diminutive and dwarfish size. Certainly, Dr. Jekyll implies this when he theorizes that "man will be ultimately known for a mere polity of multifarious, incongruous, and independent denizens"--that is, evil and good and many other qualities will ultimately be found to make up the entire man. However, Jekyll and his experiments can only prove at the present moment that man's existence has two parts--one good and one evil. Jekyll's experiment, which Lanyon found so horrifying, was an attempt to separate the two components, and when he discovered the correct formula and drank it, Jekyll was approaching a robust fifty years of age; yet after his transformation into Edward Hyde, he felt younger, lighter, and more sensual. He knew from the beginning that he was "tenfold more wicked [and] evil."
As often noted in the above commentaries, after the transformation to Hyde, Jekyll "had lost in stature." He was much smaller as "the evil side of [his] nature . . . was less robust and less developed than the good." This observation obviously contradicts the critics who see Jekyll/Hyde as being 1/2 good and 1/2 evil. Hyde, therefore, as the evil part of man, is less than the total man, but he is nevertheless an important part of the total man. This is represented in the scene when Hyde looks in the mirror and sees himself as "natural and human": He was "conscious of no repugnance, rather a leap of welcome." This is, of course, because Jekyll sees Hyde as a part of himself. And yet, from Chapter 1 onward, everyone who encounters Hyde is utterly horrified and repulsed by his pure evil. Ultimately, Jekyll himself will come to look upon Hyde as his "errant son" who must be punished.
As Hyde, then, all sorts of pleasures were indulged in. It is never mentioned what the exact nature of all the secret, depraved, disreputable acts was, but most people (perhaps because of the movie versions of this novel) consider these "vulgar" acts to have something to do with sex. In the minds of the late Victorians (late nineteenth century), evil and sex were synonymous, and certainly to such a highly respectable and eminent man as Dr. Jekyll, it would have been extremely disgraceful if he were to have been discovered in some sort of illicit sex. Of course, we know that, as Hyde, he did murder Sir Danvers without provocation, but no other crimes were ever attributed to him; after the murder, however, all sorts of tales surfaced concerning his disreputable life and his vile actions. Therefore, since he was never charged with any other specific crime, most readers do assume that his vileness, vulgarity, and villainy were associated with sexual matters--matters which a dignified and respectable scientist could not be associated with, but activities which he, as Jekyll, had pursued in his early youth and now could once more enjoy in the person of Hyde, while the respectable Jekyll remained perfectly safe from detection.
Even after the murder of Sir Danvers, and Jekyll vows to give up the "liberty, the comparative youth, the light step, leaping impulses, and secret pleasures that I had enjoyed in the disguise of Hyde," the extreme enjoyment he receives as Hyde is ultimately why Jekyll cannot put Hyde aside. Jekyll thoroughly enjoys, vicariously, the multifarious, decadent activities performed by his double.
Thus, Jekyll's enjoyment of Hyde's activities allows Hyde to grow in stature, and of the two men, Hyde is slowly gaining the ascendancy over Jekyll. The mere fact that Jekyll never gave up the house in Soho (rented for Hyde) nor destroyed Hyde's clothes is proof to us that the vow he made to Utterson in Chapter 5, after the murder of Sir Danvers ("I swear to God I will never set eyes on him again. I bind my honor to you that I am done with him"), was indeed a hypocritical or empty vow. Even though Jekyll did try for two months to lead a "life of such severity," the Hyde in Jekyll was constantly struggling for release. Repressed for so long, when Hyde emerged, he "came out roaring." Jekyll now has to contend with his "lust of evil," with the "damned horrors of the evenings," and with"the ugly face of iniquity" which stared into his soul. Hyde is not to be denied because, secretly, Jekyll still desires his presence and his activities. But he also knows that if he lets "Hyde peep out an instant . . . the hands of all men would be raised to take and slay him." Therefore, Hyde is trapped by his own evil ways and is confined to the laboratory.
However, when Jekyll is sitting peacefully one day in Regent's Park, in broad daylight, he feels all of the symptoms of Hyde emerging without the aid of the chemical potion. Hyde appears because Jekyll, who has so long tried to deny and suppress him, subconsciously desires that he appear again. But the appearance must be concealed, and so Jekyll/Hyde--by now, it is difficult to separate the two--conceive of a plan to get their revenge on Dr. Lanyon, who has so often ridiculed Dr. Jekyll and has refused to even contemplate the possibility of an evil side of his nature existing. Thus, the elaborate scheme involving Lanyon--the letter written by Hyde, but in Jekyll's handwriting--allows Jekyll/Hyde to achieve their revenge against Dr. Lanyon.
From this point on, until Utterson and Poole break down the door, Jekyll/Hyde have an even stranger relationship with each other. Jekyll hates Hyde for the ascendancy that Hyde has over him, and Hyde hates Jekyll both because of Jekyll's hatred, but more importantly because Hyde knows that Jekyll can destroy him (Hyde) by committing suicide as Jekyll. The final irony is that Jekyll is the one who commits suicide (the evil Hyde, of course, would never do this), but during the act of Jekyll's dying, Hyde regains the ascendancy so that Utterson and Poole find not the body of Jekyll, but that of Hyde.
