By means of a kinetic test, it was demonstrated that one of the folding intermediates (Iα) of hen lysozyme with α-domain folded and β-domain unfolded is on the folding pathway under the classical definition. Iα folds to the native (N) state directly (unfolded (U) [hArr] Iα [hArr] N) without having to unfold to U and then refold to N through alternative folding pathways as in Iα [hArr] U [hArr] N.