Those who neglect the means are kept from the light by their own fault
Thesis XV. 'But if others, unlike these,' he continues, 'have neglected the means and aids within their reach, put out the sparks born in them, and, as Paul says, held down the truth in unrighteousness, then it is no fate or divine decree but their own fault that shuts them out from the clearer light.'
This is in the Epitome of Theology already cited, page 244.
Latin
XV. Quod si autem, inquit, alii horum dissimiles, quae praesto sunt media & auxilia neglexerint, igniculos innatos restinxerint, & veritatem, ut ait Paulus, in injustitia detinuerint, non certe aliquo fato, aut divino decreto, sed propria sua culpa ab illustriore lumine prohibentur. In jam citata Epitome Theologiae pag. 244.