In the aftermath of the 2020 pandemics, monetary policy has been tightened owing to the unpreceeding return of inflation in many advanced economies. In this quest for stability, a renew of interest emerged concerning the concept of natural rate of interest in the footsteps of Knut Wicksell’s works. Setting nominal short-term rates to target a low inflation rate under a policy rule has always been presented as the three building blocks of a Wicksellian monetary policy fashion (Lavoie and Seccareccia, 2004; Clinton, 2006). However, the Wicksellian label was more motivated by the monetary policy rule making and the effectiveness of short-term rates to fight price level instability, rather than paying attention to the natural rate of interest as a policy guide for tracking inflation (deflation). It seems that the situation has changed following the pandemics. The return of inflation in 2020, mostly due to chain-value gluts and supply shocks at large, pushed academics and policymakers to examine new framework and key concepts for understanding inflation dynamics. In this veil, a renew of interest emerged for the natural rate of interest as the Bank for International Settlement (BIS) did quite recently. It is, thus, a good opportunity to come back, or to discover, the leading contributions made by Wicksell as Professor Trautwein contributed in many ways to do all along his career.