Critic Dennis Walder suggests that Lewis Nkosi in Tasks and Masks is "particularly persuasive on modern African poetry." Nkosi cites Ranaivo, Rabearivelo, Rabemananjaro as cosmopolitan Malagasy poets; Walder suggests that these poets "elicit from Nkosi close and sympathetic attention, and a convincing application of his overall argument - announced at the start as an obsessive idea that African writers are 'easily divisible' into two groups: those who see their society as unchanging, like a mask turned perpetually in the artist's hands, 'each time revealing nothing more than what it is, the work of some skillful carver who originally imparted to it its outstanding features'; and those writers who conceive 'of the act of writing as the carrying out of social tasks'." Walder writes, "As Nkosi applies this distinction, the remarkably rich and varied literary manifestations of the continent do begin to fall into a kind of order. And its application enables the critic to proceed to the level of insight which relates the different uses of, for example, traditional Malagasy folk poetry - the so-called hain-teny or proverb formula - by the poets concerned, to their respective personal and class positions: Rabearivelo, the 'deracinated' intellectual whose reworking of the hain-teny conceits read like translation; and Ranaivo, the rediscoverer of his own culture who integrates the hain-teny into his work, thus bringing together 'task' and 'mask'."