Final answer:
The missing premise in the student's logical argument on suffering and morality could be 'We have the ability to reduce suffering,' connecting the value judgments with actionable capabilities.
Step-by-step explanation:
The student's question involves constructing a logical argument around the premises concerning suffering and morality. Given the provided premises of 'Pain and suffering are bad' and 'It's good to reduce the unnecessary suffering in the world,' a missing premise could pertain to the capability and responsibility of acting upon the recognition that suffering is bad and that reducing it is good. An appropriate missing premise (P3) might be: 'We have the ability to reduce suffering.'
This proposed premise connects the acknowledged value judgment (suffering is bad, reducing it is good) with the implication that action is possible and thus, implied or recommended. It aligns with the philosophical concept that understanding suffering, its causes, and recognizing the path to alleviate it — echoing ideas similar to the Buddhist Four Noble Truths — is essential in ethical decision-making.