“Raskolnik“, in Russian, means “one who splits.”
Indeed, Raskolnikov committed a homicide by splitting his victim’s brain with an axe. The crystal clear purpose of an axe itself is “to split”.
It is apparent that Raskolnikov prospected that an axe would be the optimal weapon of choice for an immaculate murder, as he anticipated that a knife would potentially cause turbulence. His objective was to undertake a methodically coherent crime scene, erring the potency of perturbation that would lead to jeopardy, both physically and mentally.
The question remains—a dichotomy: did Raskolnikov engage in a rational act irrationally, or an irrational act rationally? Through indirect characterization within the narrative, revealing that Raskolnikov embraced the reckoning of Western pragmatism instead of Christian morality, Raskolnikov was idiosyncratically in the stance of the former [to himself]. As the topic of emotion vs. reason is up to quarrel, this thought may be conveniently substantiated by what the axe truly epitomize.
The axe figuratively slit the rational and the irrational in this sense: when Raskolnikov chopped the pawnbroker’s brain, he not only murdered the woman (corporeally), but also murdered the self (psychologically and intellectually).
During the homicide scene, Raskolnikov’s sanity was outstripped by groundless apprehension, which thwarted his elevating expectations—a treacherous operation without a maneuver tackled without the vulnerability of trauma vanquishing the cognitive mind. Raskolnikov had symbolically fractured his own rational mind through an irrational act that he once surmised as rational.
The double-sided feature of the axe, the dulled side utilized to butcher Alyona, and the razor edge to inadvertently kill Lizaveta, may then represent or personify the duplex nature of Raskolnikov.
In closing, the axe is an instrument created for rational practices, but has been exploited irrationally as a weapon, akin to the cerebrum of Raskolnikov.