[1] Finlay was educated at St Augustine's College, Cavan, and became a novice of the Society of Jesus in 1866, at the Jesuit theological faculty, Milltown Park, Dublin.
There he encountered Prussian agricultural methods and the Raiffeisenbank system; and gained an interest in biology from colleagues.
At St Beuno's Finlay started The Lyceum, the college magazine, in the year he arrived, but could not induce Hopkins to contribute.
[5][6][7] Finlay in 1880 was ordained priest, and in 1881 he was made head of St Stanislaus College in Tullabeg, replacing William Delany.
In 1883, under Delany from December, he became joint professor at University, with his brother Peter, of mental and moral science.