This book presents a concise treatise of critical thinking, embodying its most important elements, into a compact, convenient, organized, and easy to understand form. It is intended as a handy go-to reference source to help anyone or any organization develop sound reasoning and arguments. Key elements •What critical thinking is (and is not), its uses and its limitations•How critical thinking relates to the human understanding process•The five steps to becoming a critical thinker•An argument checklist•Five appendices of critical thinking hindrances (biases)The original version was hosted on Skepdic.com beginning in 2004. Since that time it has become internationally adopted or referenced by educational institutions, medical institutions, militaries, government agencies, blogs, and newsletters as a handy guidebook on critical thinking. This second edition has been updated to include a new appendix on hindrances due to natural biases. The book is available in both eBook and paperback formats.