He had certainly not come unscathed out of the society of those persons of "liberal opinions" with whom he consorted in Irvine; and he expressly attributes to their lessons the scrape into which he fell soon after "he put his hand to plough again." He was compelled, according to the then all but universal custom of rural parishes in Scotland, to do penance in church, before the congregation, in consequence of the birth of an illegitimate child. But not the amours, or the tavern, or drudging manual labour could keep him long from his true calling. "Rhyme," he says, "I had given up [on going to Irvine], but meeting with Fergusson's 'Scottish Poems,' I strung anew my wildly sounding lyre with emulating vigour." It was probably this accidental meeting with Fergusson that in a great measure finally determined the Scottish character of his poetry.
Just before their father's death, Robert and Gilbert took the cold and ungrateful farm of Mossgiel, in the parish of Mauchline, to which the family now removed. The four years of Burns's connection with this place were the most important of his life. It was then that his genius developed its highest energies; on the works produced in these years his fame was first established, and must ever continue mainly to rest; it was then also that his personal character came out in all its brightest lights, and in all but its darkest shadows; and indeed from the commencement of this period the history of the man may be traced, step by step, in his own immortal writings.
Burns now began to know that Nature had meant him for a poet; and diligently, though as yet in secret, he laboured in what he felt to be his destined vocation. He was never more productive than at this time, when he wrote such skits on the kirk and its associates as "The Twa Herds" (pastors), "Holy Willie's Prayer," "The Holy Fair," and "The Ordination." "Hallowe'en," a descriptive poem, perhaps even more exquisitely wrought than "The Holy Fair," also belongs to the Mossgiel period, as does an even more notable effort.
Burns had often remarked to his brother that there was something peculiarly venerable in the phrase, "Let us worship God," used by a decent, sober head of a family introducing family worship. To this sentiment we are indebted for "The Cottar's Saturday Night," the hint of the plan and title of which were taken from Fergusson's "Farmer's Ingle." It is, perhaps, of all Burns's pieces, the one whose exclusion from the collection, were such a thing possible nowadays, would be the most injurious, if not to the genius, at least to the character of the man. In spite of many feeble lines and some heavy stanzas, it appears to me that even his genius would suffer more in estimation by being contemplated in the absence of this poem than of any other single performance he has left us. Loftier flights he certainly has made, but in these he remained but a short while on the wing, and effort is too often perceptible; here the motion is easy, gentle, placidly undulating.