Which element did Beccaria propose as necessary for effective punishment?

Beccaria, a prominent figure in classical criminology, emphasized the importance of certainty in the application of punishment as a crucial element for it to be effective. He argued that for punishment to deter crime, individuals must be certain that they will face consequences for their actions if they commit a crime. The idea is grounded in the notion that the fear of punishment can discourage potential offenders from engaging in illegal activities.

When punishment is certain, it directly influences the individual's decision-making process, leading them to weigh the risks against the potential rewards of committing a crime. This concept is foundational to Beccaria's principles and has significantly shaped modern criminal justice systems, which aim to ensure that laws are enforced predictably and fairly to maintain social order.

The other options, while they may have merit in different contexts, do not capture the essence of Beccaria's perspective on what makes punishment effective in deterring crime. Beccaria did not prioritize flexibility, public approval, or mere accessibility in the same way he underscored the necessity of certainty, making it a cornerstone of his ideas on punishment and deterrence.