In the De rerum natura, at 2.7-8, Lucretius references ‘holding serene temples’ (tenere..templa serena). Scholars have previously suggested that this refers to holding onto symbolic temples of philosophy. That is to say, scholars have assumed that Lucretius hereby encourages us to live philosophical lives. I argue that ‘holding serene temples’ refers to keeping peaceful minds (i.e. practicing ataraxia). I develop philological argument to support my interpretation and thereafter consider the proem of Book 2 in light of my suggestion. I find that Lucretius, in his proem, celebrates the manner in which living an Epicurean life offers one lack of bodily pain (aponia) and lack of mental pain (ataraxia). Thus, while the proem has regularly been read as a non-Epicurean ‘purple passage’ I argue that, in the proem, Lucretius develops mainstream Epicurean doctrine. The talk is a contribution toward studies of the peacefulness and calm-mindedness that Epicureanism advocates.