There seem to be two schools of thought about the meaning of the motto on Pope Francis's coat of arms:
miserando atque eligendo
These words are taken from the 21st homily of the Venerable Bede, describing Jesus's first meeting with Matthew:
Vidit ergo Jesus publicanum, et quia miserando atque eligendo vidit, ait illi, ‘Sequere me’.
One school of thought, represented by Fr. Z, says that the phrase has two ablative gerunds and describes Jesus's way of seeing: "by showing compassion and by choosing." Fr. Z would translate the sentence "Jesus, therefore, saw the publican, and because he saw by having mercy and by choosing, He said to him, ‘Follow me.'"
Ron Conte, representing the other school of thought, says that's a literal, word-by-word translation that misses the meaning, as such an approach to translation often does. Conte would translate the motto "pitiable yet chosen", and the whole sentence “Then Jesus saw the publican, and because he saw [him to be] pitiable and yet elect, he said to him: Follow me.” Most commonly, the motto is translated "lowly but chosen."
My problem with Fr. Z's interpretation is that it doesn't make sense. What does it mean to "see by choosing"? My problem with Ron Conte's interpretation is that I don't understand the grammar.
Miserando and eligendo appear to be ablatives describing vidit. Or perhaps there are some elided words and the sentence should be understood like this:
Vidit ergo Jesus publicanum, et quia [eum] miserando atque eligendo [esse] vidit, ait illi, ‘Sequere me’.
But I still don't understand that. What does it mean to use an ablative gerund as a predicate like that? Why not a gerundive, like eum miserandum atque eligendum esse vidit? Does the fact that miseror can also be understood as a deponent verb play a role here? Might these actually be dative gerunds?