"Sarcasm I now see to be, in general, the language of the devil; for which reason I have long since as good as renounced it"

Sarcasm emerges here as a subject of moral critique, positioned as not just a rhetorical device, but as an inherently negative force. The author frames sarcasm as "the language of the devil", thus linking it with deceit, temptation, and spiritual corruption, a view that echoes traditional religious suspicion towards clever speech that misleads or wounds. Rather than simply dismissing sarcasm as unkind or rude, he elevates the conversation to a matter of deep ethical principle. By attributing sarcasm to the devil, he suggests it is fundamentally allied to malice, division, and a turning away from sincerity and constructive discourse.

The language of the devil invokes associations of manipulation and a pleasure in subverting truth for its own sake. Sarcasm relies on a veneer of irony, saying the opposite of what is meant, often to ridicule or criticize under a cloak of wit. Such a mode of speaking, Carlyle implies, replaces transparent communication with antagonism, making genuine connection and understanding impossible. It transports daily interaction into a combat of veiled insults, where one's cleverness is exercised at the expense of another's dignity or good faith.

Notably, the author acknowledges personal experience with sarcasm, revealing a prior familiarity, perhaps even habitual use. Yet, guided by reflection, he has "as good as renounced it". This phrase indicates an active, deliberate turning away, motivated by an understanding of the corrosive nature he now attributes to sarcasm. It is not merely a casual avoidance, but a near-total rejection, as one might shun a vice after perceiving its true character.

Underlying the statement is an advocacy for earnestness and sincerity in human relations. The retreat from sarcasm becomes a philosophical stance, aligning the speaker with the ideals of candor and benevolence. In renouncing sarcasm, he seeks not only personal moral clarity but a model of communication founded on mutual respect and trust.