Facing suspicions about his "Irish" roots and his association with New Licht theologian John Simson (then under investigation by Scottish ecclesiastical courts), a ministry for him in Scotland was unlikely to be a success, so he returned to Ireland to pursue a career in academia.
Bagaimanapun, menemui kecurigaan tentang akar "Irlandia"-nya dan asosiasinya dengan teologian John Simson (kemudian di bawah penyelidikan oleh mahkamah ekselsiastikal Skotlandia), kementrian di Skotlandia kelihatan tidak akan sukses sehingga dia meninggalkan gereja dan kembali ke Irlandia untuk mengejar karier di akademia.