The article by Christopher M. Dobson explores the vast chemical space encompassing all possible small organic molecules, including those present in biological systems. Despite the immense size of this space, only a fraction has been explored, yet these explorations have significantly advanced our understanding of biology and drug development. Biological systems have evolved to perform controlled chemistry in an aqueous environment, using enzymes and other macromolecules to synthesize, transport, and degrade various compounds. However, the number of biologically relevant small molecules is orders of magnitude less than the total possible number of small carbon-based compounds. This limited diversity is remarkable given the complexity and richness of biological processes. The article highlights the importance of understanding the link between natural proteins and small molecules used in biological systems, as well as the role of synthetic small molecules in drug discovery. Techniques such as X-ray crystallography, nuclear magnetic resonance, and mass spectrometry have revolutionized our understanding of biological molecules, and modern imaging techniques like cryoelectron tomography are providing detailed insights into cellular structures. The challenges of drug discovery are discussed, emphasizing the need for compounds that can modulate disease processes without interacting with other cellular components. The article also explores the potential of using natural products and their derivatives as "chemical tools" to probe biological systems and discover new therapeutics. The development of new technologies and computational methods is crucial for efficient drug discovery, and the article calls for interdisciplinary collaboration to fully leverage these advancements. Finally, the article looks ahead to future prospects, including the creation of public databases of chemical information and the establishment of Molecular Libraries Screening Centers to facilitate the exploration of chemical space and the development of new drugs.The article by Christopher M. Dobson explores the vast chemical space encompassing all possible small organic molecules, including those present in biological systems. Despite the immense size of this space, only a fraction has been explored, yet these explorations have significantly advanced our understanding of biology and drug development. Biological systems have evolved to perform controlled chemistry in an aqueous environment, using enzymes and other macromolecules to synthesize, transport, and degrade various compounds. However, the number of biologically relevant small molecules is orders of magnitude less than the total possible number of small carbon-based compounds. This limited diversity is remarkable given the complexity and richness of biological processes. The article highlights the importance of understanding the link between natural proteins and small molecules used in biological systems, as well as the role of synthetic small molecules in drug discovery. Techniques such as X-ray crystallography, nuclear magnetic resonance, and mass spectrometry have revolutionized our understanding of biological molecules, and modern imaging techniques like cryoelectron tomography are providing detailed insights into cellular structures. The challenges of drug discovery are discussed, emphasizing the need for compounds that can modulate disease processes without interacting with other cellular components. The article also explores the potential of using natural products and their derivatives as "chemical tools" to probe biological systems and discover new therapeutics. The development of new technologies and computational methods is crucial for efficient drug discovery, and the article calls for interdisciplinary collaboration to fully leverage these advancements. Finally, the article looks ahead to future prospects, including the creation of public databases of chemical information and the establishment of Molecular Libraries Screening Centers to facilitate the exploration of chemical space and the development of new drugs.