After the instability of the Middle Ages and the relative lack of innovation regarding human progress, time had come for change. With the influences from the Arabic world and a re-acquaintance of European intellectuals with the works of ancient authors, by the thirteenth century new ideas began to emerge. This led to a broad awakening throughout Europe, and plants were examined from original observations. Disease and pestilence were rampant in Renaissance Europe, and plants were viewed as having curative properties, perhaps so designed by God to ameliorate human suffering. The workers who took special interest in plants, often physicians, were called herbalists and their books were referred to as herbals. The invention of printing by moveable metal type in 1454 in Germany helped the diffusion of botanical information in descriptions and illustrations for plants growing in central Europe. This period did not result in comprehensive new botanical classifications but much was developed in terminology, descriptions, and improvements with illustrations. These tools would be needed for the appearance of the early formal botanical classifications in the sixteenth and seventeenth centuries.